As big of an Iron Maiden fan as I am, I have found myself so focused on the game and shots so much that I didn't even care what song was playing in the background nor did I notice it... it just blurs into the background as I play the game. The playfield and game is that intense during my good games. The multi-balls and modes are pure adrenaline. At the end of a ball I've sometimes had to stop and think about the music because I haven't paid attention to it. The game is that good to me.
I have owned about 50 machines over the past 10 years, and not many have felt this good to play this early on. The only other one I can think of is Iron Man, and that's been in my collection for a solid 7+ years.
May sound like I'm pumping the game, but I really don't have any interest in trying to sell it to anyone, just want to share my experience to provide feedback for those considering it.
And I agree that this is not about Iron Maiden the band, this is about the Legacy of the Beast game so the modes are more about accomplishing something related to the game (IE, powering up the pyramid) than traditional band games (IE, earn backstage pass, on tour, etc.).
Oh, and have I mentioned how satisfying it is to hit the loops on this game? Damn good.