They don't appear to support OS X, Win 98, ME or NT, with their proprietary plug-in.
Why would you patronize Wal-Mart in the first place? They promote low prices by stiffing employees out of wages and communities out of tax revenues (both theirs and that of the local competition they destroy). Sorry if that seems a tangential question, but this being a message board I feel it's as valid a place as any to use this opportunity to point out that while Wal-Mart will not go out of their way to see to your needs, you could just as easily get the music without going out of your way to patronize the Enron of the retail world.