PaulaThis is the sound chip in the Amiga. It also controls some ports such as the joystick ports and the floppy. It, too, offloads the CPU by using DMA.
All sound in the Amiga are sampled waveforms; there's no synthesizer chip and no programming of instruments.
The DMA reads up to a few samples per scanline to be ready in time for Paula to output them at the set rate to four sound channels, two in the left speaker and two in the right. There's no way to mix or pan this hard stereo separation.
You can turn the sound DMA off and output wave buffers on a CPU interrupt to make your own software synthesizer, but of course this is very heavy on the CPU. Decent sample rates are far above the performance of an unexpanded OCS Amiga.