One of my favorite MLB traditions is the walk up song. To my knowledge, no other sport pauses the action and lets each individual player have a soundtrack to his introduction. The walk up song serves a number of key functions. Most obviously, it provides a window into the personality of the player; additionally, it creates a musical association with the player that fans are likely to latch on to.
For me, erstwhile Rockie Ryan Spilborghs will forever be linked to the annoying--but undeniably catchy--Gwen Stefani song that he played before his at-bats in 2009. You know, the song that goes, "Whoo-oo...WHOOO-OO". Most importantly, though, the walk up song has to prepare a player to hit the ball, and hit the ball hard.
In a way, the walk up song is like a Rorschach ink-blot test. There's no real "right" answer to what works. There are, however, wrong answers. Just like there would be negative consequences in telling your psycho-therapist that every ink-blot looks like demonic clowns devouring kittens, there are negative consequences to choosing a bad walk up song. Understanding what works and what doesn't is crucial to picking the best song for you.
First thing's first: you have to pick a song that is personally meaningful. Sure, tens of thousands of people are listening (and judging...always judging), but they aren't the ones digging into the batter's box. You are. That doesn't mean the song has to lay bare the yearnings of your deepest soul; it just has to be a song that you personally enjoy, no matter the context. If you're a rock fan, play a rock song. If you're into hip-hop, go with hip-hop. If you're all about country, develop new tastes (haha, just kidding, country's fine).
Second--this is obvious, but it's crucial--the song needs to have a killer hook. Whether it's a barn-busting intro, a rousing chorus, or a shredding guitar solo, your walk up song needs to turn the amp up to eleven and thrash. That's why so many players have gone with Crazy Train, or Kashmir, or (insert AC/DC song). Leave your soft rock and smooth jazz at home; the walk up song is about angrying up the blood.
I also caution against using whatever is the ubiquitous pop song du jour (looking at you Tulo). There are reasons for this beyond your thoughts on the musical merit of the Justin Biebers and Carly Rae Jepsens of the world. You hope to have 300+ at bats at your home ballpark in a year; do you really want to hear the same bouncing chorus from a sprightly pop star that many times?
Further, you have to add the number of times you hear the song on radio, at supermarkets, on TV...pretty soon you might actively hate your walk up song. Finally, the life spans of these songs are short, and shrinking all the time. You might think that picking the Harlem Shake is a cute idea now, but I guarantee you that, come June, only massively uncool people will still care about it. Everyone else will have moved on to the next big thing. You want to pick a song with a little more resilience.
So, now that we've outlined some attributes to aim for and pitfalls to avoid, the musical world is your oyster. There is, however, a final piece to the puzzle, and it's the most undefinable aspect to the whole ritual. The snippet of song you've chosen has to make you want to hit a baseball really freaking hard. Rhythm and sound correlate remarkably well with certain physical actions; some songs make you want to slow dance, just like some songs make you want to jump up and down in a mosh pit. I would hazard a guess that every human being in the world knows a song that burrows deep down into his or her gut, and activates a desire to pick up a club and start smashing. You just have to figure out which song does that for you.
For me, that song is The House That Heaven Built by a band called Japandroids. The intro is a face-melting guitar riff, followed by rousing, take-no-prisoners lyrics. When the drums kick in, it's just pure ear-candy. But of course, what works for one person won't work for everyone, and I encourage readers to share their own choices for their ideal walk up song.