My phone has the extremes on it. I literally have A to Z (April Wine to Zappa - or Abba to Zebra) on it. I have some heavy metal (not death metal - that makes me ears bleed) and classical music (Mozart and Beethoven). I have the classics (Free, Zepplin, Queen, Beatles, Kinks etc) the "Hair Bands" (Poison, Warrant, Def Lepard, Giant, etc), the Arena Bands (Styx, Journey, Genesis, etc), and Progressive Music (Yes, Rush, Dream Theater, etc)
But lately I have been listening to Pandora (or now IHeartRadio since it has a Pandora station feature that is commercial free until the end of the year). I set up a station for an old band that few people outside of Florida know (Unless they are TSO fans) - Savatage. That "Station" as introduced me to "new" (some are older some are new) bands that I am really enjoying like NightWish, Hammerfall, Dreamland, Dragonfire, Rhapsody, Edguy, Primal Fear, etc. So, needless to say - these groups are now also on my iphone. . .