Like Bear said, that's the only way. I use iTunes Match, but it's not a back up. I use
Crashplan for my back ups. It has unlimited back up, not badly priced I think. I have a main computer that has all my music, photos, and movies and that gets back up. If you pay for 4 years it comes out to $3.96 a month (they have 1-4 year packages), or you can pay month to month for $5.99 a month.