Just trying to find one as an inside joke for a friend's wedding, and so far Lowe's, Home Depot, Michael's, Joann Fabrics, Hobby Lobby, Target, and Wal-Mart have all come up empty.
I can vouch for the quality of Music of the Spheres. I played with some in Giddings a while back while picking up a few bottles of Special **** at a hardware store on the south east side.
I'm not sure where in HD you looked, but I am certain I saw some when I was in there yesterday (the shop in Dripping Springs where I live). Did you ask anyone who works there? IIRC, they weren't really in an area where you'd expect to find 'em.