Over at the rcarduino blog Duane has published some interesting methods of making sounds with Arduino using algorithmic music. The concept is quite complex yet simple - by using a mathematical formula whose result is sent to a PWM pin, a varying sound can be generated.
The beauty of the sounds is the minimal code required to generate them - after listening a few times you can image these coming from computers of days gone by. Duane's example allows playback of multiple tunes by pressing a combination of buttons, with a reasonable effect - for example:
So if this sort of project intrigues you and you're new to Arduino, the best way to learn is with out new Experimenter's Kit for Arduino:
The package includes a wide variety of parts, sensors and modules including: a servo motor, lights, buttons, switches, sound, sensors, breadboard, wires and more. Furthermore a Freetronics Eleven Arduino-compatible board is included to make this an extensive hobby experimenter, inventor and starter kit. However we don't leave you alone to figure it all out, included is a great project and instruction booklet, plus access to a supporting web page and software examples. In other words - this is everything you need to get started for a fun range of electronics and Arduino related projects!
So to get started or for more information and to order, check out the product page.