Why

288 independent analyses of this recording were submitted to AcousticBrainz. All but a handful of them — 97% — put it in C major, a key signature of no sharps and no flats. The tempo printed above is the median of the 288 readings; 98% of them land within 2% of it, and they barely differ at all.

At 90.8 BPM one beat lasts 660.8 milliseconds, so a sixteenth note is 165.2 ms and a dotted eighth 495.6 ms — the delay times for this recording. Counted half as fast it is 45.4 BPM, counted twice as fast 181.6. A score would mark that Andante, by the ranges this site uses.

The analyses put the reference pitch of the recording at 434.2 Hz, which is 23 cents below concert A at 440 Hz — the sort of drift a tape machine or a slightly different mastering leaves behind. That is a fact about this transfer of the music, not about how it was played.

The dynamic complexity of the recording measures 3.46 dB: that is how far the level wanders from its own average, so a small number means a loud, flat master and a large one means a recording that still breathes. Its average loudness is 0.737 on Essentia's 0-to-1 scale, which is not decibels and is not comparable to a streaming service's number.

10 other recordings here are in C major; the ones listed below are the closest in tempo.