This circuit designed by Antonis Pontikakis. It's used ATmega32 microcontroller as the main part. At the circuit, there are 2 24LC32 eeprom memories, the 1st for internal standard melodies and the 2nd one is for user's compositions.
As control, he created a menu that will be appeared on 4x20 LCD (Liquid Crystal Display). For browsing the menu there are 6 buttons in front of circuit's box (Menu, Up, Down, Enter, Start, Stop). All firmware only use 19 Kbytes flash memory of ATmega32 microcontroller writen in C compiled used Code Vision AVR compiler. If you need for more information don't be hesitate to send him an email.