I was just talking to someone about what she's going to do because her Mac is too old to be updated to Lion and use the iCloud. The iCloud will make sharing between all your Apple devices [computer, iPad, iPhone, AppleTV] much easier, the idea being that the information/material is in the 'cloud' and resourced by the devices when needed/wanted. [n.b., nothing is totally safe, so you're wise to have backup copies of your most important and irreplaceable things, whether they're in the cloud or not = Murphy's Law].
Thinking a bit, I realized that I'm doing this myself now [I don't yet have iCloud]. I'm not sure about music [but since they're digital files they can be copied elsewhere, I think]. I have the following Cloud accounts, all free: 3GB at Dropbox, 5GB at SugarSync and 5GB at Evernote. With each, but particularly with dropbox and Evernote you can email things to your account and they will be there for you. Then you go to your desktop or iPad or iPhone apps [all free] and access the document or item you need. Remember that anything you take out of the Dropbox on the Cloud or computer/pad etc. is removed, not copied and moved.
So, go to Dropbox or Evernote or SugarSync [I'm sure there are others!] and read the explanations for what you get. You can run some tests [after all, they're free] and see which you like. At least til you join the iCloud, this might be sufficient.
[I'm researching cloud computing as backup storage and hope to write about that in the near term.]
