Why does Spotify speed up playback?

[daladams]

Music recorded at 85 bpm, should not be played back at any other speed. I have noticed that Spotify's playback speed is faster than the originals in ever single case so far, regardless of whether I use Bluetooth or wired connections. 
Altering art is beyond distasteful, and will ultimately keep a lot of people from comitting to this service

[zarcothellis]

A lot of old radio stations (especially pop stations) used to and probably still speed up songs by up to 3% to get more commercial time. It's annoying AF. I just played a song listed as 2:34 so I ran a stop watch and the song finished at 2:24. Disappointing, Spotify.