# Musical instrument cases, bags & instrument stands: research notes Date: 2026-10-25. Scope: products that enclose an instrument for transport (hardshell cases, flight cases, gig bags) or that hold an instrument upright for access when it isn't being played (instrument stands — guitar/bass, violin/viola/cello/double bass, wind, brass, and keyboard stands). Taxonomy: `supplies > gear > musical_instrument_cases`. Excluded, and why: **music stands** (the kind that hold sheet music) belong to the sibling leaf `metronomes` ("Tuners, Metronomes & Music Stands") — a different object from an *instrument* stand, and the two are easy to confuse by name alone, so I kept this register to stands that hold the instrument itself. **In-case humidifiers and hygrometers** (Dampit, Oasis and similar) belong to `musical-instrument-care` ("Musical Instrument Care & Maintenance"); a case's interior pocket for one is in scope here, the device itself is not. **Playing straps** (worn on the body while playing a guitar) and other playing accessories belong to `musical-playing-accessories`; the shoulder/backpack straps on a case or gig bag, used to carry the case, are a different object and stay here. **Case hardware as spare parts** (replacement latches, hinges, wheels bought separately) belong to `musical-instrument-parts`; the same part as a feature of the case as sold is in scope here. **Drum hardware** (cymbal, snare and hi-hat stands, bass-drum pedals) has no sibling leaf in this catalog and isn't "instrument stands" in how the trade itself organizes the category — Hercules Stands' own navigation (fetched, see Sources) groups stands by "Fretted & Bowed", "Winds & Percussion" (percussion here means mallets/triangles etc. carried like a wind accessory, not a drum kit) and "Keyboard", with no drum-hardware category — so I left drum hardware out rather than silently absorb a product family nobody else is assigned either. Camera bags and cases are a separate sibling leaf (`camera-bags`) even though they sit in the same `gear` group; not covered here at all. Quote labels: **verbatim** = text I read myself (pdftotext on a downloaded PDF, or curl followed by my own regex HTML-stripping, which counts as reading the raw page per the skill's own definition) or the fetch tool returned it in quotation marks; **fetched excerpt** = WebFetch (the AI-summarizing tool) summarized or reworded the page; **search excerpt** = a search-engine summary because the page itself would not load. WebSearch reported its budget exhausted for this session before I ran a single query, so every claim below is from a direct fetch, a curl, or an Internet Archive snapshot — there are no search-excerpt-only numbers in this register, by necessity rather than choice. ## Seed Seed run (recorded verbatim from the brief): - Example: olive-oil `harvest_date` — "a facet that experts rank first, that almost no listing carries, and that is expensive to backfill... list it, mark it researched, and limit backfill to the top of the catalog," with `months_since_harvest` as the derived metric hanging off it. - Persona: "A pastry chef, who thinks in ratios, temperatures and why a recipe fails." 1. **The equivalent of harvest_date is whether a case was ever actually tested to ATA Specification 300, rather than just styled to look like one.** Experts (touring professionals, cartage companies) rank this first because it is the one thing that decides whether a case survives repeated airline handling; almost no retail listing states it, because "ATA case" on a title is marketing for the shape, not a certification claim (Wikipedia's ATA case entry, verbatim: "The term ATA case is frequently used to describe cases that resemble those that comply with ATA Specification 300 category I or II, but have not been certified by the independent testing defined in ATA Specification 300."). Confirming real certification means reading the manufacturer's own compliance claims, which is exactly the olive-oil pattern. **Kept** as the top value of `shell_protection_level`, marked `researched` for the certification claim specifically, with backfill limited to top-ranked touring-grade cases — and the checked-baggage dimension sum is the derived metric that hangs off the same shell-tier decision, playing the role `months_since_harvest` played for harvest date. 2. **The pastry chef's instinct is to ask about the ratio of protective material to total bulk, and about what happens outside the temperature band the thing was designed for.** Applied here: a chef would ask how much of a case's weight and thickness is actually foam doing protective work versus decorative shell (which is the real difference between a semi-rigid case and a hardshell of similar size, and became the ordinal `shell_protection_level` facet), and would ask what a closed car trunk or an unpressurised cargo hold — both well outside normal room temperature — does to a wood instrument's glue joints and varnish over a touring season. **Dropped** the thermal-exposure facet itself: no case brand or standard I could reach publishes a temperature rating for a case, so there is nothing sourced to hang a facet on (see "Trimmed detail" below for where this is kept as a note instead of a fabricated spec). ## Sources and what each supports ### Regulator **14 CFR Part 251, Carriage of Musical Instruments (GovInfo, fetched as raw XML via curl, then regex-stripped and read as text — verbatim)** https://www.govinfo.gov/content/pkg/CFR-2023-title14-vol4/xml/CFR-2023-title14-vol4-part251.xml - verbatim §251.3 (small instruments, free carry-on): carriers "shall permit a passenger to carry a violin, guitar, or other small musical instrument in the aircraft cabin... if (a) The instrument can be stowed safely... and (b) There is space for such stowage at the time the passenger boards." - verbatim §251.4 (large instruments, carry-on): permitted if "(a) The instrument is contained in a case or covered so as to avoid injury to other passengers; (b) The weight of the instrument, including the case or covering, does not exceed 165 pounds... (e) The passenger wishing to carry the instrument in the aircraft cabin has purchased an additional seat to accommodate the instrument." - verbatim §251.5 (large instruments, checked baggage): permitted if "(a) The sum of the length, width, and height measured in inches of the outside linear dimensions of the instrument (including the case) does not exceed 150 inches... (b) The weight of the instrument does not exceed 165 pounds." - Supports: the checked-baggage derived metric, the carry-on-needs-a-seat judgement, the 165 lb figure used in two judgements and one visual grammar. Confidence high — this is the primary legal text itself, in the lamps register's phrase "single source but the primary document." I tried to reach a second, plain-language restatement (DOT's airconsumer site, the TSA instruments page) and could not (see "Could not reach"). ### Standards body **ATA Specification 300, Revision 2008.1, Air Transport Association of America (PDF hosted historically by Anvil Cases, read via an Internet Archive snapshot since anvilcase.com itself no longer serves it; pdftotext — verbatim)** https://web.archive.org/web/20140308045616/http://www.anvilcase.com/pdfs/ATA300SPECRev2008.pdf - verbatim: "Category I Reusable for a minimum of 100 round-trips / Category II Reusable for a minimum of 10 round-trips / Category III Usable for a minimum of 1 trip." - verbatim Table B-2-1.1 (drop test, containers ≤50 lb gross): "160 Drops at 30 in." (face, Category I) / "16 Drops at 22 in." (face, Category II); 80 edge drops at 36 in. (Cat I) / 8 at 27 in. (Cat II); 40 corner drops at 36 in. (Cat I) / 4 at 27 in. (Cat II). Heights fall as gross weight rises (e.g. face drop height drops to 18 in. at 150 lb, 16 in. at 200 lb+). Figures match Wikipedia's ATA case entry's restatement of the same table, below — two independent reads of the same underlying numbers. - verbatim B-2-3: "Category I containers shall be resistant to normal precipitation." - verbatim B-2-4: vibration tested "within the range of 5 to 50 cycles per second for a period of not less than two (2) hours," Category I only. - verbatim B-2-5: penetration test, Category I only, "a bar of 3.2 centimeters in diameter with a hemispherical end, weighing 6 kilograms," dropped 0.5 m onto the weakest point. - Supports: the ATA 300 category definitions (mechanism, shell_protection_level, protection ladder grammar, one tradeoff, two judgements). Confidence high — this is the spec itself, reached only because a case manufacturer had hosted a copy and the Wayback Machine kept it; I could not find it on the Air Transport Association / Airlines for America's own site, where it is normally sold rather than published (see "Could not reach"). ### Primers (Wikipedia) **Wikipedia, "ATA case" (also serves "Road case" and "Flight case," which redirect to the same article) — curl, HTML-stripped, read as text, verbatim** https://en.wikipedia.org/wiki/ATA_case - verbatim: "A road case, ATA case, or flight case is a shipping container specifically designed to protect musical instruments, motion picture equipment, audio and lighting production equipment, props, firearms, or other sensitive equipment." - verbatim construction: "An outer layer of ABS or fiberglass laminate is adhered to a middle layer of lightweight 3⁄16-to-1⁄2-inch (4.8 to 12.7 mm) cabinet-grade plywood such as birch, poplar, or maple... an internal shock-absorbing filler such as polyurethane or polyethylene foam has cavities that correspond to the shape of the components... corners... commonly reinforced with stamped sheet steel." - verbatim: "The term ATA case is frequently used to describe cases that resemble those that comply with ATA Specification 300 category I or II, but have not been certified by the independent testing defined in ATA Specification 300." - verbatim: "Caster wheels are often built into or attached to the case for ease of transit." - Supports: the mechanism's shell description, the ATA-style-vs-certified judgement (confirmed against the spec PDF itself, above — this is the "two sources" case), the carry_system wheels value. Confidence high; this article is tagged on Wikipedia as needing more citations, which is why I verified its numeric claims against the ATA 300 PDF directly rather than trusting the article alone for anything load-bearing. **Wikipedia, "Gig bag" — curl, HTML-stripped, read as text, verbatim** https://en.wikipedia.org/wiki/Gig_bag - verbatim: "A gig bag (or gigbag) is a padded, soft-sided bag used for the storage and transport of musical instruments, most commonly a guitar or bass guitar... most gig bags include pockets for storage of sheet music, instrument cables, picks, straps, and other accessories, along with shoulder straps and grab handles." - verbatim: "While gig bags are lighter and easier to carry, they offer much less protection than padded hard shell or wooden cases. As such, some musicians will own both soft gig bags and hard shell cases for their instruments... use the gig bag for local rehearsals, session work, and gigs, and use the hard shell case if their instrument will be checked onto airline baggage." - Supports: the product_form definition, the gig-bag-vs-hardshell tradeoff, the "own both" judgement, weather_resistance's rationale (fabric is the weak point). Confidence high; this single article carries two separate judgements in this register because it is the one reachable source that states the trade-off in plain terms, and it reads as settled trade knowledge rather than a contested claim, so I did not treat the lack of a second source as a problem requiring a confidence downgrade — but I flag it here for the blind check. ### Spec sheets (brand sites, fetched directly or via Internet Archive) **Hercules Stands — "About Hercules" (Internet Archive snapshot of herculesstands.com/about, 2020; curl, HTML-stripped, verbatim)** https://web.archive.org/web/2020/https://www.herculesstands.com/about - verbatim product navigation: "FRETTED & BOWED INSTRUMENT" (Guitar, Folk Instruments, Ukulele, Violin, Cello, Double Bass, Accessories), "WINDS & PERCUSSION" (Flute, Clarinet, Saxophone, Trumpet, Flugelhorn, Trombone, French Horn, Low Brass, Percussion, Combination, Accessories), "KEYBOARD" (Straight/Boom, X Stands, Z Stands, Benches, Accessories). - Supports: the instrument_family split's groupings and the decision to exclude drum hardware (no drum-stand category exists in a leading stand maker's own taxonomy). Confidence high for what the page itself says; I'm using a single brand's taxonomy as evidence for how the trade organizes stands, which is a reasonable use of a spec_sheet source per the skill's own guidance (good for the canonical facet list) but I note it is one brand, not a standards body. **Hercules Stands — guitar stand category page, live HTML fetched directly from the 2020-10-29 Internet Archive capture (live herculesstands.com returns 404 on this path today; curl, HTML-stripped, verbatim)** https://web.archive.org/web/20201029084647/http://herculesstands.com/products/fretted-and-bowed-instrument/Guitar/ - verbatim (GS412B PLUS and GS414B PLUS listings, same figures on both): "The AGS yoke is designed to accommodate more guitar neck sizes from 40 mm – 52 mm (1.57” - 2.05”) including classic, acoustic, electric and bass guitars. The attached N.I.N.A. (Narrow Instrument Neck Adjustment, HA301) are specially designed to increase the thickness of AGS arms to accommodate narrow neck instruments from min. 28 mm (1.10”) like banjos and mandolins." - verbatim (GS405B): "shock-absorbing system... Specially Formulated Rubber Foam fully protects instrument at all contact points." - Supports: the `fit_range` facet's numbers (40–52 mm, extendable to 28 mm), the stand half of the mechanism section, the neck-width judgement. Confidence medium for generalizing beyond Hercules: this is one brand's own spec, repeated identically across two of its own product lines, which tells me it's a real design constant *for that brand's AGS system*, not that every competing stand brand publishes or meets the same number — the judgement says so explicitly. **Hercules Stands — keyboard X-stand category page, same 2020-10-29 Internet Archive capture (curl, HTML-stripped, verbatim)** https://web.archive.org/web/20201029084647/http://herculesstands.com/products/keyboard/X-STANDS/ - verbatim (KS110B): "The EZ-LOK System automatically locks the stand in place... Round and square 25.4 mm (1") steel tubing for strength and stability." - verbatim (KS210B, double tier): "height is adjustable from 198 mm (7.8") to 300 mm (11.8") in 25.4 mm (1") increments." - verbatim (KS118B, KS100B): fold/trigger-height descriptions, "stores in 88% of the space it takes to store a full size keyboard stand" (KS100B). - **No maximum load figure appears on any of the five models on this page.** I looked specifically for a weight-capacity number to source `load_capacity`'s range and found none, which is itself the fact recorded in that facet's `listing_field_hint` — I did not invent a number to fill the gap. - Supports: `folds_flat`'s rationale, the locking-mechanism detail in the mechanism section's stand family (trimmed — see "Trimmed detail"), and the honest absence behind `load_capacity` having no `range`. Confidence high for what's on the page, which includes the absence. **Hiscox Cases — site navigation, hiscoxcases.com (curl, HTML-stripped, verbatim; live site, 200 status)** https://www.hiscoxcases.com/ - verbatim category list under "Violin, Viola & Cello": "Violin Shaped / Violin Rectangular / Viola / Cello." Also verbatim: "Case Backpacks / Shoulder Strap / Additional Pads" under Accessories. - Supports: `interior_fit`'s "Violin Shaped vs Violin Rectangular" naming example, from a leading string-instrument case brand's own catalog structure. Confidence high for the naming convention; I could not reach their "Protection System" technology page (404 on every path I tried — see "Could not reach") so I have nothing from Hiscox on shell material composition. **BAM Cases — site navigation, bamcases.com (curl, HTML-stripped, verbatim; live site, 200 status)** https://www.bamcases.com/ - verbatim top-level case lines: "SHOP BY LINE: SEMI-RIGID/SOFT CASES [list of named product lines] / HIGHTECH CASES [list of named product lines]." Also verbatim under "REPLACEMENT PARTS (ALL)": "BOW RETAINERS / CELLO WHEELS / COMBINATION LATCH / HIGHTECH LATCH / LOOP HANDLE." - Supports: the semi-rigid/hardshell split in `shell_protection_level`'s values, and `carry_system`'s wheels value (cello wheels sold as a named, replaceable part confirms wheels are a real, recognized feature on this instrument's cases). Confidence high for the taxonomy; every page below the homepage I tried on this domain (FAQ, technology, about, story) returned 404, so I have nothing from BAM on their "Hightech" material's actual composition and did not claim anything about it. ## Data points used for derived metrics - `checked_baggage_sum_in`: 150 inches summed (length + width + height) and 165 lb, both from 14 CFR 251.5 (verbatim, single primary-source regulation, see above). No second source reached despite trying (DOT airconsumer, TSA — both blocked; see "Could not reach"); treated like the lamps register treated ENERGY STAR V2.2, as the primary document standing alone. ## Against the existing add-on schema `zamana-expertise/data/schema-parts/supplies/gear/add-ons/musical_instrument_case.jsonc` currently has exactly one field: `tsa_flight_approved` (boolean | null). The `gear-standard` add-on (shared across musical-instrument and camera gear) has `compatibility_raw` (string). `supplies-standard` gives every item in this vertical `high_signal_markdown` and the shared `sizing` block (dimensions, weight, capacity, pack_count). Proposals only; nothing in zamana-expertise was edited. - **`tsa_flight_approved` is noise, and worse, it names a certification that doesn't exist.** TSA screens carry-on items by X-ray; it has a real "TSA-approved" program for *luggage locks* (Travel Sentry), but no program that approves a case for flight. The actual governing facts are federal (14 CFR 251, which obliges carriers, not cases) and industry (ATA Specification 300, which some cases are tested to and most "ATA case" listings are not). Recommend dropping `tsa_flight_approved` and replacing it with a *category quality currency* field: `flight_case_rating`, enum `[none, ata_style_uncertified, ata300_category_i, ata300_category_ii]`, which is this register's `shell_protection_level` collapsed to just its flight-relevant top two values plus the certification distinction. This is dense and augmentable (a brand-page lookup per product, same cost profile `tsa_flight_approved` would have had) and it actually corresponds to something real. - **A hard filter is missing**: `product_form` (hardshell / gig bag / stand) and `instrument_family` (the split values in this register) are not represented anywhere in the add-on or the shared gear standard, and both are present on essentially every listing title. These are the two facts a buyer filters on before anything else in this category and belong in the add-on as hard filters, not left to markdown. - **A currency field is missing for the stand segment**: `fit_range_mm` (numeric, min/max) for guitar/bass stands specifically — dense on brand spec pages per this register's `backfill_note`, though not on marketplace titles, so it would need the same brand-page backfill effort `tsa_flight_approved` would have needed, just pointed at a real number. - `interior_fit`, `carry_system`, `weather_resistance` and `load_capacity` are, by this register's own `backfill_cost` (medium, low, low, high respectively) and by rule 4 of AGENTS.md, better suited to `high_signal_markdown` than to structured fields — none of them is dense enough on listings to guarantee augmentation on every row, which is the bar AGENTS.md sets for a schema field versus markdown material. I did not propose structured fields for them. - Visually-derived facts (shell color, exterior finish, whether a case "looks" shaped from its product photo) are deliberately absent from this register per AGENTS.md rule 1; they belong to the image pipeline. ## Branches - `product_form` = stand → ask `fit_range`, `folds_flat`, `load_capacity`; `shell_protection_level` and `interior_fit` become irrelevant. Chain: a stand has no enclosing shell to rate and nothing shaped around the instrument to speak of — its whole job is the yoke/cradle width and whether it collapses (Hercules Stands' category pages, above, describe *only* fit, locking and folding for stands, never a shell tier or an interior lining). SUPPORTED. `carry_system` and `weather_resistance` also become irrelevant on this branch, but that leg is WEAK, not SUPPORTED: the Hercules citation never addresses handles, straps, wheels or rain exposure for a stand. The conclusion rests only on the facets' own wording (`carry_system` is defined as "handles, straps or wheels built onto the case or bag"; `weather_resistance` as "water-resistant fabric and zippers or a fully sealed shell") — a bare stand has neither a case/bag body to carry nor fabric/zippers/shell to weatherproof, by definition rather than by citation. Kept uncited because the conclusion is uncontroversial, per the lamps/honey/coffee precedent for defensible-but-uncited branch legs. - `product_form` = hardshell/flight case or gig bag → ask `shell_protection_level`, `interior_fit`, `carry_system`, `weather_resistance`; `fit_range` and `folds_flat` become irrelevant. Chain: those two facts are specifically about a stand's yoke mechanism and fold-down frame (Hercules Stands' keyboard and guitar-stand pages, above); a case or bag has neither. SUPPORTED. `load_capacity` also becomes irrelevant on this branch, but that leg is WEAK: the Hercules citation names "yoke mechanism and fold-down frame," not a weight rating. The conclusion (a case or bag carries no stand-style load rating) is uncontroversial and kept uncited for the same reason as above, rather than cited to a source that doesn't actually reach it. - I did not add a branch from `shell_protection_level`'s top value ("ATA-style or ATA 300 certified") into the checked-baggage derived metric, even though they're conceptually linked, because the derived metric depends on `sizing.dimensions` (a shared schema block), not on a facet id this register defines, and the branches field can only name facet ids. The link is stated instead in the metric's own `why` and in judgement 2. ## Trimmed detail - `shell_protection_level`'s `why_experts_care` had to drop the specific drop-test numbers (160 face drops at 30 in for Category I at ≤50 lb, etc.) to fit the 80-word cap; they're recorded verbatim above under the ATA 300 source and in the judgement note's intent, even though the judgement text itself also had to stay short. - The mechanism's keyboard-stand detail (patented EZ-LOK locking, 25.4 mm steel tubing, the double-tier's 198–300 mm second-tier range) didn't fit the 150-word mechanism cap or warrant its own facet at this register's thinness — recorded here so it isn't lost, and because it's the direct evidentiary basis for `folds_flat` and for `load_capacity` having no `range`. - The thermal-exposure idea from the seed persona (car trunks and cargo holds as a temperature extreme instruments weren't built for) is real buyer-relevant knowledge but unsourced for any brand or standard; it's recorded here rather than turned into a fabricated facet or range. - Hiscox's and BAM's deeper technology pages (their foam/composite shell material claims) were unreachable (see below), so this register's shell-material description stays at the ATA-300-sourced generic level (ABS/fiberglass/plywood/foam) rather than naming any brand's proprietary material. ## Could not reach WebSearch reported its session budget exhausted before I ran a single query, so every item below was a direct-fetch or curl attempt, not a missed search. DOT's airconsumer musical- instruments page and fly-rights page (403 both via WebFetch and curl); TSA's musical- instruments "what can I bring" page (404 on every path guessed; the general "whatcanibring/all" page loaded but did not mention instruments by name); old.reddit.com r/violinist and r/Guitar wikis (403, and WebFetch separately refused reddit.com entirely); Reverb's and Guitar World's buying-guide pages (403/404); Andertons' and Dawsons' blog buying guides (404); Sweetwater's three insync buying-guide URLs I tried for cases and stands (403 each); stringovation. connollymusic.com (DNS does not resolve — likely a wrong subdomain guessed without search); Shar Music and Southwest Strings case-buying-guide pages (404/403); Gator Cases' and SKB's product and ATA-case pages (403, or 200 but pure Shopify JS with no server-rendered spec text); Hiscox's "Protection System" technology page under three guessed slugs (404 each); BAM's FAQ, about, story and "hightech" technology pages under several guessed slugs (404 each, same Shopify-404 pattern as other retail sites in this house's prior runs). None of these would have been load-bearing beyond what's already double-sourced above, except the DOT/TSA pages, which I wanted only as a second source for the FAA figures and did not get. ## Corrections (2026-10-26) - Fixed `checked_baggage_sum_in`'s formula to convert `sizing.dimensions.length/width/height` to inches (divide by 2.54 when `sizing.dimensions.unit` is `cm`) before summing, instead of summing raw numbers and labelling the result inches regardless of unit (Required fix 1). - Reworded `shell_protection_level`'s split question to "Soft gig bag, semi-rigid, hardshell, or ATA flight case?", naming all four facet values directly so the mapping from answer to value is stated rather than implied, and anchoring it in instrument-specific terms instead of generic "sturdy case" wording (Required fixes 2 and 3). - Added `weather_resistance` to the case/gig-bag branch's `then_ask`; it was already excluded on the stand branch but had never been asked on the one branch its own definition is scoped to (Required fix 4). - Rewrote the branch chain text for `carry_system` and `weather_resistance` (stand branch) and `load_capacity` (case/bag branch) to say plainly that these three legs are WEAK, not SUPPORTED — the cited Hercules pages never reach handles/straps/wheels, rain exposure, or weight ratings — and kept them only because the conclusion follows from the facets' own definitional scope and is uncontroversial, per the lamps/honey/coffee precedent for uncited-but-defensible branch legs (Required fix 5). - Raised `folds_flat`'s `backfill_cost` from "none" to "low" to match `carry_system` and `weather_resistance`, which have the identically scoped "title or bullets" keyword-match hint (Required fix 6). - Required fix 7 (single-sourced 150in/165lb and 40-52mm/28mm figures) is a flag, not a defect — both are already disclosed and confidence-scoped in the judgements; no change made.