Carly Rae Jepsen's "Call Me Maybe" is among the more obnoxious pop music hits in recent memory, but the song only becomes doubly grating when sped up with chipmunk vocals. If you're wondering who to thank for that listening privilege, honors go to Ryan Challinor. But it turns out this experiment involves more than a bit of sound manipulation. No stranger to the ins and outs of music (Challinor's Google+ page reveals he works for Harmonix), he noticed some similarity between the tempo of music and the range of a human's heart rate. So it seemed like a logical step to directly link the two. By relying on a running wristwatch (with integrated heart rate monitor) he hacked together some code in Max/MSP that ultimately allowed him to modify a given song's tempo based on heart rate. Below you'll find the result of Challinor's effort, which he's submitted for Music Hack Day MIT 2012.