A friend has an old iBook and has been told buy the Apple repair shop that the reason it doesn’t work properly is because he’s running OS10 and should go back to OS9. I don’t think he uses it for anything other than managing his music.

So is iTunes pre OS10 (I can't remember if it was about back then) and will it work on a purely classic system?

I had a look on the Apple site for system requirements but it was all confusing!