When a guy kicks off his album with a tune featuring words ”freely adapted” from a Percy Bysshe Shelley poem, it’s a safe bet the proceedings are about to get pretentious. Not so with San Francisco’s John Vanderslice. His fourth CD, Cellar Door (Barsuk), is a well-conceived collection of odd pop songs with thoughtful lyrics about unusual subjects. ”Promising Actress” pays tribute to the film ”Mulholland Drive” (”Sometimes a cowboy’s just a man in a cowboy suit”), while ”Heated Pool and Bar” tackles weightier fare (”My friend is based in Afghanistan/He goes from cave to cave and pulls the trigger at the first sight of a man”). Vanderslice is a classic gear geek — he owns the Bay Area’s popular Tiny Telephone, where Death Cab for Cutie and others have recorded — and ”Cellar” is full of instruments, electronics, and studio tricks. Fortunately, none of it ever feels gratuitous. The songs stay with you as much as the sound.