Tie Your Mother Down

157 independent analyses of this recording were submitted to AcousticBrainz. Fewer than half of them — 49% — put it in D major, a key signature of 2 sharps. The tempo printed above is the median of the 157 readings; 14% of them land within 2% of it, and the middle eight tenths of them run from 134.9 to 151.9 BPM. That is a recording the detector cannot settle on — the readings are spread far enough that the median is a summary of a disagreement rather than a measurement anybody should trust to the decimal.

At 143.5 BPM one beat lasts 418.1 milliseconds, so a sixteenth note is 104.5 ms and a dotted eighth 313.6 ms — the delay times for this recording. Counted half as fast it is 71.8 BPM, counted twice as fast 287. A score would mark that Allegro, by the ranges this site uses.

The analyses put the reference pitch of the recording at 435.4 Hz, which is 18 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 2.36 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 0.749 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 D major; the ones listed below are the closest in tempo.