BPM Analyzer gives you the tempo of all of your MP3s
Creating playlists can be tedious, and every bit of information can help. While some people maintain the ID3 tags in their MP3 files in excruciating detail, others (like me) can't seem to find the time. But when it comes to finding the tempo, no amount of manual ID3 tag maintenance will help.
If you're trying to put together a playlist that contains songs that are a similar speed, knowing the beats-per-minute of each song is immensely helpful. Luckily, there is a free download called BPM Analyzer from MixMeister that will analyze all of your MP3 tracks, and update the ID3 tags in them with exact BPM information. With that done, it's a simple matter of sorting your music library by the beats-per-minute field.
Now you can put together an upbeat energy-boosting playlist full of fast songs, a mellow playlist with slower songs, or pretty much anything you desire. And for the nerds like me, it's just another piece of information to sort and group your music by.
BPM Analyzer is available on both the Windows and Mac operating system.