This is the time of every year that “This is Just a Modern Rock Song” becomes my favorite Belle and Sebastian song. (Taking over from “Lazy Line Painter Jane” or “The Boy With the Arab Strap,” which rule at other times.) Because now that summer is all-but-technically kaput, and we can finally put the Great Shorts Debate behind us, at least for another seven or eight months, I most often find myself pulling on a pair of corduroy pants in the morning