Creating an amazing confluence of events, this morning I hear a report on NPR about this research, get a comment from Tim Rutherford-Johnson about the same article, and get a Technorati trackback of Forrest Covington's take on my catchy tune question.
First, Forrest's view: catchy tunes are very paradigmatically tonal-like (reduce easily in Schenkerian analysis) and related to the overtone series. Could be, though I can think of a few objections to the overtone idea. The overtone series is not based upon the composition of the air, but rather upon modes of vibration for any simple harmonic motion. A string, or air in an open-ended pipe or close-ended cone (length = L), will vibrate in ratios of L/2, L/3, L/4, L/5, etc, which creates frequencies along the overtone series. This fact can be used to support notions of concurrent interval and chord consonance and dissonance, but has little effect on melody construction (other than bugle calls).
Second, the article cited by both the BBC and NPR is horribly mischaracterized by both news outlets. The BBC says that the article tells us "how tunes get stuck in your head." NPR's print version is better, "The iPod of the Brain," but the intro on the radio program was similar to the BBC. Kraemer et al make no claims to explain how the tunes get stuck in the brain, they just provide proof of auditory imagery - the imagining of music in the mind without outside stimulus. They would play music to participants while scanning their brains. Activity noticed in the auditory association cortex continued during silent gaps in familiar tunes (and did not continue in unfamiliar tunes). Nothing is mentioned or discovered as to what makes a familiar tune catchy, or even why the auditory cortex does remember the tunes. One fascinating result from this study is that music with text limited activities to the auditory association cortex, whereas instrumental music produced activity that spread from the auditory association cortex to the left primary auditory cortex. The authors interpret this result as showing how text provides semantic knowledge to fill in gaps, the instrumental music required more brain power to recall the missing music. This relates closely to visual imagery, happy news to Gestalt music psychologists.