Since sound is a big part of what I do for a living, Garage Band and Audacity are on my list of regular tools.  I find audacity is really good for doing things like changing the tempo of an mp3 (to dance to for instance) and I use garage band with my kids because it is easy.

I had a Student who dug around and found this software for PC which is strikingly similar to Garage Band in many ways (for those of you who don’t have a  Mac)  They have a free trial if you want to check it out.

http://www.acoustica.com/mixcraft/

I have also embedded a little tune that my kids did as a project (their own composition) I liked it! UBC WordPress seems to be clipping the mp3 to mere seconds, which is frustrating, so I have linked it to a google page. (there are ways around this!)

Student Sample