Sometimes one ends up discussing angels on the head of a pin, I guess.
I seem to remember writing that it was the interaction of these items that provided the innovation? The fact that Apple had the computer, the software, the music playback unit, and subsequently also provided the music download.
The rest is history.
To keep these posts short, there's little reason to go into nitty-gritty detail. Apple bought SoundJamMP and redesigned it, adding CD-ripping (which was the whole point, getting people to move their music into their computers), and also removing the recording feature, since that would be in contravention of the agreement Apple had/has with Apple Records.
Tomorrow, Apple launches a new visualizer for iTunes, also purchased from an outside source.