this is something I knocked up as I had a little bit of spare time, and I thought I'd share it as it amused me.
It plays tunes that come out on the PWM pin (portB2 - pin 5 on the ATtiny24v), you just need to filter it (a simple RC filter will do) + an amp or speaker, etc
The tunes are easily edited, so you can program you own melodies.
If you do give it a go then post them and I'll look forward to listening.
All the best
NB : There's an improved version 2 of the software (a few posts below)