BPM for iPod DJing
Whist the iPod and iTunes are fantastic in their own right and offer tons of functionality, they have a major short coming, you can’t alter pitch on the iPod, or iTunes, to alter pitch you need DJ specific equipment to do this, which can be costly. However, as mentioned here, there are solutions to this iPod short coming.
Why is altering pitch so important for DJing? simply because of Beatmatching. Beats are matched from one channel to the other altering the pitch has the effect of altering the BPM (beats per minute) of the track. Assuming you’ve organized your music in the format shown here, you’ll be able to DJ music within the same BPM group, this will allows you to bypass the inherent flaw in DJing on the iPod.
BPM is calculated using various software that you can find free online, here are a few that you might be interested in:
iTunes BPM inspector
Vocalist BPM inspector
Whippinpost BPM inspector
Alternatively youc an calculate BPM by counting the number of beats in 15 seconds, then multiply that by 4.
You want to make sure you calculate BPM consistently on the most stable beat, so if your doing breakbeat you might find counting the cymbals more effective than the kick drum or snare for example.
Once you’ve got the BPM for a track it will make DJing with that track on an iPod a lot easier, and a lot more fun.