If you're a batter then you want a quick clip from something that's going to pump you up and get the crowd excited. "Welcome to the Jungle" or "Hell's Bells" are perfect. Anything from Ride the Lightning would be fine too. I'm a big fan of The Beastie Boys but I'm sorry, "Girls" is not a good choice here. Picking the rap-du-jour usually leads to changing your music a lot after something falls off the charts but if you blare Nelly in St. Louis or 2Pac in Oakland then you're good to go.
I think there's no better example of how a piece of music can send a message for a ball player than if you're a closer coming in to pitch the 9th. Once you leave the bullpen, you want your music to let people know that you're coming in to kick some ass and be home in time for dinner. Here are three great examples of what I'm talking about.
The man shares his name with a legendary horror movie villain who spawned the entire stalker "can't be killed" genre. Why not use his music? I remember watching him come into the playoffs against the Yankees in 2004 and once the music started playing the entire crowd at Fenway went nuts. Five thumbs up for creativity.
A certain first-ballot Hall of Famer who enters to the song "Enter Sandman." Classic. I remember this song playing as we used to run onto the field for football in high school and that was in front of maybe four thousand people. Always used to fire me up.
A few years ago Billy Wagner got traded to the Mets and started to enter the ballgame to the same music. The song is fantastic and is just about perfect for a closer coming in to shut the door but some people just have trademarks and you don't mess with 'em. MJ and his tongue, the Icky Shuffle, and Enter Sandman. For shame Billy.
Rick "Wild Thing" Vaughn
Rick Vaughn has had his fair share of problems. Juvenile detention, adultery, etc...But it was his vision problems that led to a few pitches juuuust a bit outside the strike zone and the nickname Wild Thing. Once he got that fixed (and got rid of the ladies glasses) he could throw the heater with pin-point control. Cleveland Municipal Stadium never sounded so good.