The bpm-tools is a command line tool to automatically calculate and tag the tempo (in beats-per-minute) of music files. It reliably detects the tempo of the vast majority of popular music I have used it with, and is a useful tool for DJs and use with xwax on Linux, and scripting on the command-line.
Right now the code serves as the best explanation of the algorithm — a relatively simple application of an autocorrelation by statistical sampling. As yet, there is no scientific comparison of the algorithm with others software.
bmp-tools is available in Ubuntu Software Center for Ubuntu 13.10 Saucy. For Ubuntu 13.04, Ubuntu 12.04, Ubuntu 12.10, you may install it from PPA by running below 2 commands one by one in terminal (Ctrl+Alt+T):
sudo add-apt-repository ppa:dholbach/ppa sudo apt-get update; sudo apt-get install bpm-tools