Microsoft Chairman Bill Gates said his company is exploring ways to develop a music download service similar to Apple Computer's iTunes that would tie into the software giant's multimedia applications. Responding to questions at an analyst meeting here Thursday, Gates indicated that any music store project would be more a matter of providing computer users with added convenience - and presumably, keeping people using Microsoft software - rather than a direct moneymaker. "It's maybe a feature your platform should offer, but it's not like you're going to make some (big) markup," Gates said.