The original SublimeLoop made with the MUPROC (Music Processor) a simple 4 track sequencer (“DAW”) for the BBC Micro that just drove its internal soundchip (the TI SN76489).
Probably sometime around 1986.
Quora question : Who wrote the MUPROC?
Download the MUPROC disc-image (for the BeebEm)
Now there's a BBC emulator that runs in the browser. (And yes, the Muproc seems to work fine on it.)