I've convinced myself they included ELO just for me. There are those tracks, like Nina's "I Wish I Knew How It Feels to Be Free", The Sweet's "Blockbuster" and T-Rex's "Rock On" that I already had and think are fantastic and then some songs that are quite new to me. I'm obsessed with Frankie Miller's "I Can't Change It" - I adore it, even if it did replace "Wild Horses" in episode four - it's so raw and just... it kills me. Thin Lizzy's "Whiskey in the Jar" is also awesome. Oh, oh! And Lindisfarne's "Meet Me on the Corner". Love.
The whole thing does make me yearn for an 'original score' soundtrack, though. I love Ed's score.
Which brings me to a stupid question - the track at the beginning of 2.05, after the CG tribute - is that an original track, or a song I don't know? It's absolutely fabulous. ETA - buzzylittleb informs me it's Hawkwind - which I had actually pegged, but didn't put down for fear of looking foolish, but hey, the joke's on me.