Came across this study through a post by Tom Jacobs over on Miller-McCune. Here's the Abstract:

The present study investigated whether and how a musical rhythm entrains a listener's visual attention. To this end, participants were presented with pictures of faces and houses and indicated whether picture orientation was upright or inverted. Participants performed this task in silence or with a musical rhythm playing in the background. In the latter condition, pictures could occur off-beat or on a rhythmically implied, silent beat. Pictures presented without the musical rhythm and off-beat were responded to more slowly than pictures presented on-beat. This effect was comparable for faces and houses. Together these results indicate that musical rhythm both synchronizes and facilitates concurrent stimulus processing.

Kinda cool huh? From my own study - I have seen how music can help performance - but it's interesting to see a rhythmic component come into play. Tom quotes from the study that they speculate that rhythm can affect "attention allocation policies", which apart from sounding totally awesome - does kinda make sense; once you identify a regular beat - it makes up part of your aural environment that is now predictable - the brain starts to look for it - to expect it. If you expect to see something - i.e. - if you know it is coming and you have an idea of the direction in which it will appear - it is likely that you're going to see it faster than if you weren't expecting it.

I believe that music acts like a "warm-up" for the brain; it stimulates background neural activity which enables it to move information faster - analagous to an athlete warming up - you get better performance when the muscles are stimulated than from a cold standing start. Add rhythm as a tool to indicate to the brain when to selectively focus, remove the lyrics so you don't get distracted by someone else's story and you're talking about the best work enhancing tool ever invented - music to work to.

Image Credit: Dave Makes - Flickr