Combining this and this to create tiny music programs.
How tiny you ask? 128 bytes.
The sound generation itself takes up just 14 lines of assembly, generating 31 bytes of machine code.
The rest is taken up the ELF header and functions needed to open the sound device and outputting samples.
In case you wonder how the sound was generated, here is the relevant part of the source:
mov ebx, eax shr ebx, 14 and bl, 0x03 inc ebx mov ecx, eax shr ecx, 11 and cl, 0x07 shl ecx, 1 sub ebx, ecx mov ecx, eax shl ecx, 1 mul ebx shr eax, 1 or eax, ecx
EAX is a timer counting up at 8000hz, and at the end the lower byte of EAX is written to the audio device.
In case you don't have a computer that runs Linux or OSS you can listen to the "music" here:
Needs OSS (/dev/dsp) to run.