INDUSTRY FIELD GUIDE
Musical instrument repair reference tone data for AI
A repairer can demonstrate whether an audible change tracks an adjustment or a changed recording setup.
NAICS 811490 · Other Personal and Household Goods Repair and Maintenance
A repairer can demonstrate whether an audible change tracks an adjustment or a changed recording setup. Census includes musical instrument repair in this industry. NIST’s measurement traceability resources offer context for documenting what the reference and recording setup establish. U.S. Census 2022 NAICS manual · NIST measurement traceability
Use a shop-owned instrument and record an original isolated tone before and after an approved adjustment. Document the tuning reference, microphone placement and gain. Provide a second pair with different gain or a changed reference so a reviewer can identify a comparison that needs recapture.
Use no commercial music or customer recordings. Keep serials out of the files and obtain written permission for any performers and recording operators.
Describe a controlled instrument audio sample
Original Fiund exercise
A changed microphone gain can prevent an audible-level comparison
An owned instrument produces original isolated practice tones, represented by dummy recording metadata. No commercial music, customer recording or tuning instruction is supplied.
| Record | Source | What it records |
|---|---|---|
| IT1 | Tone pair A metadata | Before and after use reference R, microphone position P and gain G. Reviewer records a specific audible difference under that matched setup. |
| IT2 | Tone pair B metadata | Same stated instrument alias, but after-recording gain changes from G to G2; level difference observed. |
| IT3 | Review scope | No calibrated level conversion for G2 and no independent performance or durability test supplied. |
Question for the model
Which pair has matched recording conditions for its documented audible comparison, and can B's level difference be attributed to the instrument adjustment alone?
Show the reference answer and checks
IT1 explicitly preserves reference, microphone position and gain across pair A, supporting the reviewer's stated comparison under those conditions. IT2 changes gain, and IT3 supplies no correction, so B's level difference cannot be attributed to an instrument adjustment alone. Keep the recorded setup and reviewer finding separate from broader performance claims; neither pair establishes durability or a universally improved instrument.
- Attributing an output-level change entirely to repair when recording gain also changed.
- Treating a narrowly matched tone comparison as proof of broad performance improvement.
Fields to preserve
- Instrument alias and reference
- Defines the source and comparison anchor.
- Microphone position and gain
- Preserves material recording conditions.
- Reviewer finding and measurement scope
- Limits the supported audible claim.
Test another case
Keep gain fixed but change the tuning reference or microphone position. Require a new setup-comparability check rather than relying on a matching file label.
Use original isolated tones and cleared performers. Exclude commercial songs, customer sessions, serials and unapproved recordings.
Discuss a contribution
Describe the sources you control, the task they could support and what has already been checked. Use the existing-data assessment for an archive or the collection brief for a new recording project. The contributor agreement defines Fiund’s licensing authority and compensation. A guide or fictional exercise does not establish an accepted collection or a sale.