Pistonsoft BPM Detector analyses your MP3 collection to determinate the bitrates of each song. Beats per minute (BPM) is a unit typically used as either a measure of tempo in music, or a measure of one's heart rate. A rate of 60 BPM means that one beat will occur every second. The idea is that, the higher BPM a song has, the faster it should be. Hip-hop typically uses a BPM tempo of 80-100, while house music is faster: 110-140 BPM. Jungle music goes even faster: 160-185. Gabba and Speedcore exceed 200 BPM.
This information should come handy, not only to DJs having to choose the right song on the fly but also to home users. They may want in fact to play slow songs after coming back home from a tiring day, or they may prefer something more energetic as the soundtrack for their spring cleaning!
The program automatically analyses selected files and saves the beat per minute information to the music file's ID3 tag so that you'll be able to know the song's BPM with every player you use. I'm not sure about the efficiency of BPM in order to decide what a fast or a slow music is though. Bohemian Rhapsody by Queen, for example, had a BPM rate of zero while Quien Fuera by Silvio Rodriguez received a rating of 150.75. Personally, I would use the latter for relaxing moments and the former when I need to listen to something faster.
The idea of an application that can understand the type of songs we have and classify them accordingly is great but I don't think we have achieved that level with this application.