I wrote a few games on the Spectrum and as with most of its hardware limitations we managed to squeeze quite a lot out of it. My memory is very hazy, it was we

I wrote a few games on the Spectrum and as with most of its hardware limitations we managed to squeeze quite a lot out of it. My memory is very hazy, it was well over 40 years ago, but I think keeping the timing under control was was one a big hurdle. Because it was single threaded and there was effectively only one interrupt, screen refresh/flyback, so you had to intersperse the music code into the main code and juggle it to even out the note timing. I remember one game I wrote for the 16K Spectrum, and thanks to an incredibly clever & musical friend we got something like 30 seconds of a tune that had a passable resemblance to Bach's Toccata in about 20 -30 bytes of code.[1]. Every last byte mattered on that machine. [1] Not 100% on the details but it was about that. We used a combination of base notes and mathematical progression rather than just playing a score as we could get that smaller. I think I've a dot-matrix printout of the games source code somewhere, assuming the ink hasn't faded.