Remove avoidable comparison bias
Start by making sure your own chord does not overpower the recording. Set a comfortable listening level and play candidate chords quietly enough to hear the original accompaniment and melody. Use similar registers and durations when comparing them. If one version is a thick low voicing and the other a light upper triad, you may be judging texture rather than harmonic identity. A fair test changes one important variable at a time so your ears can identify what actually improves the fit.
Include the approach and resolution
Listen to a short passage that begins before the disputed chord and continues after it. A harmony that seems plausible as an isolated sound may not support the phrase's movement. Play the proposed root and quality, then try one reasoned alternative. Avoid cycling through many unrelated chords until something seems acceptable. If the bass suggests an inversion, test that specifically. If the third is unclear, compare major and minor while holding the other notes fixed. A focused question produces a more useful answer than an unfocused search for any pleasant sound.
A fair comparison between Am7 and C
Use an original four-bar progression F–G–Am7–G. Spell Am7 as A–C–E–G. Suppose a detected chart labels bar three C instead. Play C–E–G over the recording, then A–C–E–G with a low A. Both share three notes, so either can sound superficially plausible in a dense mix. The focused question is whether the A bass and its harmonic role are present, not which chord sounds richer on your instrument.
Keep the recording level unchanged between attempts. Use similar upper voicings and the same attack strength, and add or remove only the low A for the comparison. Listen once without playing after each attempt; otherwise your instrument can become the sound you think you are identifying. Include the preceding G and following G so the disputed bar has context. Record the evidence in plain language: audible low A on arrival, upper notes C and E clear, G uncertain. That is more useful than writing sounds right.
Return with fresh ears
After several comparisons, take a brief break and replay the passage without your instrument. Write down what remains clear and what is still uncertain. Use the editable AudioChords labels to preserve a checked working version, but keep speculative choices marked in your own notes. Revisit the passage during a later session if repeated listening no longer changes your understanding. When repeated comparisons stop being useful, pause instead of making another guess. The aim is a defensible accompaniment that works across the phrase, not an endless audition of possibilities or a claim that every layered recording has one perfectly obvious chord name.
Quiet is not an accuracy guarantee
If turning down playback makes the bass disappear, do not insist that quieter must be more accurate. Choose a comfortable level at which the relevant part remains audible, or use a different available listening setup without raising the volume to overpower the room. This is a practical comparison method, not a claim that low volume improves an algorithm's analysis. The uploaded file and your playback loudness are separate matters. After a few focused trials, leave unresolved details marked as uncertain. Edit an AudioChords label when you have a reason you can explain; if you deliberately choose C for a lighter arrangement, document that as a simplification rather than a correction.