This page is dedicated to those who have considered classifying their mp3 collection according to tempo, which is measured in beats per minute, or BPM. A great use of this musical measure is the creation of playlists: a playlist with fast music to play at the gym, a playlist with slow music to relax, etc.
From the Echo Nest Site: “This is an application that helps you find out whether a human or a machine is setting the tempo for your favorite music. To do this, this application generates a click plot that shows the deviations in tempo from the average over the course of a song. Songs that don’t stray too far from the average are likely to be using a click track or a drum machine to set the beat.”