How to read detection results

When you run the free detector, the headline result is a single number: the estimated A4 reference pitch. Everything else on screen supports that number. This guide explains what the A4 value means, how the detector arrives at it, how to judge whether a reading is trustworthy, and what to do once you have one.

The A4 reference is the whole story

A song’s “tuning” is the A4 reference pitch its notes align to. Every note in a track sits on a scale derived from that one anchor, so identifying the anchor tells you how the entire track is tuned. The detector works by sampling the notes it hears and matching them against tuning tables for 440, 432, and the Solfeggio anchors, then reporting the A4 reference that fits best.

That means the result is not “this song contains 432 Hz somewhere.” It is a statement about the whole track: “the scale this music is built on is anchored to A4 = 432 Hz.” If the distinction is fuzzy, what frequency means in music covers the foundations.

Interpreting the number you see

Near 440

The track is in standard tuning — the reference formalized as ISO 16 in 1955 and used for the vast majority of modern recordings. If you expected 432 (because a title promised it), the label was wrong. That happens constantly; see why uploads are often mislabeled.

Near 432

The track sits about 32 cents below standard — the shift from 440 to 432. A cent is 1/100 of a semitone, and ±50 cents is the maximum distance to a neighboring reference, so −32 cents is a substantial, unambiguous offset that detection identifies reliably.

A Solfeggio match

The Solfeggio frequencies are specific targets — 396, 417, 528, 639, 741, 852 Hz, plus 174, 285, and 963 in the extended set. In practice, music is retuned so a chosen anchor note lands on the target, which implies a particular A4 reference. When the detected reference corresponds to one of these, the detector shows the matching display name rather than leaving you to reverse-engineer the number.

In-between values

Real-world audio doesn’t always land cleanly on a table entry. A reading a few cents off 440 usually is 440 — tape speed variation, vintage recordings, or playback chains introduce small offsets. A reading floating far from every reference suggests deliberate nonstandard tuning or a pitch-shifted upload. Either way, the measured value is the truth; the nearest named reference is just the closest label for it.

Judging whether a reading is trustworthy

Watch for stability

A trustworthy result is a stable one. Let the detector listen through a sustained, melodic section and watch whether the reading settles — the quality indicator staying green means the analysis is locked onto consistent pitched material. A value that jumps around during percussion breaks or spoken sections should not be trusted until it settles again.

”Uncertain” is an answer, not a failure

When a track lacks enough pitched material — heavy percussion, dense noise, unpitched ambience — the detector says “Uncertain” rather than guessing. Treat that as real information. Tools that always output a number are silently guessing on exactly this kind of material. If you get “Uncertain,” try a more melodic section of the track, reduce background noise, or switch from microphone to tab or desktop audio capture for a cleaner signal.

Give it good input

Detection quality follows input quality:

• Prefer tab or desktop audio over a microphone when possible — no room noise, no speaker coloration.
• Sample verses and sustained passages rather than intros, fades, or transitions.
• Let it listen longer than feels necessary; more sampled notes means a better match against the tuning tables.

Everything runs on-device — the audio is analyzed locally and nothing is uploaded — so there is no cost to letting it listen as long as you like. If you’re checking music while it streams, the same reading discipline applies in the Chrome extension; see detect tuning while streaming for the setup.

From reading to decision

Once you have a stable A4 value, the decision tree is short:

1. The value matches your target. You’re done. Enjoy the track knowing, rather than hoping, that it’s tuned the way you want.
2. The value doesn’t match your target. Don’t go hunting for a different upload with a better label — measure-and-retune beats label-trusting every time. Take a file you own and shift it from its measured tuning to the target.
3. The result stays “Uncertain.” The track may simply not have enough pitched content to anchor a tuning at all, in which case retuning it to a target is equally ill-defined. Melodic material is what carries a reference pitch.

For case 2, the retuning options page lists the available paths, including a free in-browser re-tuner for single tracks. If you’re working through a whole collection, the desktop app batch-analyzes your entire library free and then retunes songs from their measured tuning to your target — worth knowing about once you’ve caught your third mislabeled file.

The habit to build is simple: read the A4 number, check that it’s stable, and act on what you measured. A detection result you understand turns every tuning claim — on uploads, in playlists, in your own library — into something you can verify in under a minute.