Something I’ve never understood about Creative Commons is the emphasis on redistribution rights.
For the most part, CC licenses focus on who can upload a copy of a file. A song under any CC license can by uploaded by anybody whose activity fits within the terms of the license. For example, the Attribution-Sharealike license allows third parties to upload copies without asking permission as long as they give attribution and use the same license on their uploads.
Who needs the right to upload? It’s not something that anybody making work under a CC license even needs to grant, since virtually of them host freely accessible copies on the web. All anybody needs to access these works is to know the URL of the original file.
With files that are already on the web it doesn’t make sense to do filesharing, so there’s no need to permit redistribution. Filesharing is purely a pain in the ass for users, who have to leave the normal browser experience and launch a dedicated piece of software. You could maybe make a case for BitTorrent as a way to spread the bandwidth load, but that relies on a level of popularity which almost no CC works attain. And anyhow, there’s no need for an explicit license to permit BitTorrent as long as the rights holder hosts the seed file, since that would very much imply that BitTorrenting was fine.
The only thing that you really need a Creative Commons license for is the ability to make derivative works, which gives you the ability to do remixes. This is genuinely useful because there is no other way to do it. Without a license to make a derivative work you are up a creek, and making derivative works is a fundamental operation for participation in culture.