Rock Band DLC includes three songs from the artist. Don't fret, dream baby, if those tracks don't do it for you, there are already plenty of solid Orbison tracks available in the Rock Band store.
There are also a couple individual tracks from KISS. Both songs are live versions of their greatest hits "Rock and Roll All Nite" and "Strutter." Chewable blood packs and pyrotechnics sold separately. Head past the break for the full DLC details.