Any question answered...

i've got a cd player from the early 2000s, and standard data cds with audio written on won't play on it. if i write the audio to a cd-r which is designed for the audio standard is it more likely to play?

Possibly, yes. Data CDs use more of the surface than originally intended. It might be that audio-specific CD-Rs have writable areas more in line with what an older CD player might expect.

There's a shop off Tottenham Court Road that I forget the name of, that specialises in pro audio gear and media; I used to buy both archival and audio-specific CD-Rs from there. Will look up the name if you want.