Rock Band songs, but your friend replies that this song, criminally, is not part of the Rock Band catalog. You argue about this point all night, ruining your dinner, drinks and, ultimately, friendship.
There's another way -- a better way, friends. A new, unofficial and free iPhone tool from developer Three Brothers Apps titled "RB Song List" lets you scan through the game's downloadable catalog on the go. Using this app, you could have resolved this hypothetical argument in seconds, and then spent the rest of the night talking about why the hell "Wake Me Up Before You Go-Go" isn't available on the Rock Band Store.