Run Blinding Lights by The Weeknd through Essentia's RhythmExtractor2013. It returns 85.4 BPM. The track is famously 171 BPM — one of the most-played tracks of the last decade, peer-reviewed by literally every DJ in the world.
This isn't a bug. It's a known property of beat-tracking algorithms: they pick the wrong tactus level for tracks where the perceived beat doesn't match the dominant onset rate. Spotify's deprecated audio_features had the same problem — entire genres came back at half their actual tempo.
This article unpicks why that happens and shows the 30-line heuristic we use to detect and correct it.
What "BPM" actually means
Most people think BPM is a single number per track. It isn't. A piece of music has a metric hierarchy — nested levels of regular pulse:
