One of my music students found a great FREE online application today while trying to make a mashup. They wanted to find the tempo bpm of a song and the key it was in, so searched for an app and found HookTheory.com This application will do that plus a whole lot more. They have a beginner music composition music theory ibook for purchase at $14.95 as well as two wonderful online applications that are totally FREE. This interface is slick and easy to use and it will even create a notated score using western notation and even tabs if needed. Composing is simple and fun. Everything is colour coded and the application will even suggest chords to go with your melody. Checkout THEORY TAB for composing. The snap shot below gives you an idea of how everything look. Pretty straight ahead and if you have trouble figuring things out there is an online manual with video tutorials. CHECK IT OUT YOURSELF ONLINE.