MAGNETIC FIELDS frontman Stephin Merritt is widely known for being "difficult," a reputation confirmed and reinforced with every awkward interview the man gives (not to mention a demeanor that's equal parts Eeyore and Droopy Dog). It is immediately clear in Strange Powers, a new documentary about Merritt and the Magnetic Fields, that this prickliness is not some act affected for nosy interviewers—the 44-year-old is a genuine oddball, demanding, self-centered, and a bit plagued by his own intellectual superiority.

He's also wicked smart and very funny, qualities revealed here through fly-on-the wall documentation of Merritt's routines (he writes songs in gay bars, listening to bad disco) and interactions with friends, bandmates, and a ubiquitous Chihuahua.

While a rough sketch of Merritt's idiosyncrasies certainly emerges, it's to the credit of filmmakers Kerthy Fix and Gail O'Hara that Strange Powers is largely a document of a musician, not of a musician's personality. Plenty of screen time is given to footage of the Magnetic Fields performing—they're an outstanding live band, and the charisma and energy captured here makes Strange Powers a must-see for its concert footage alone. (Not to mention goofy archival photos of Merritt as a teenager.)

Equally compelling are scenes of Merritt actually writing songs. His relationship with collaborator and manager Claudia Gonson is one of the most interesting in contemporary music—the two have been performing together for 20 years—and watching them bicker over song structure is both musically insightful and quite touching.

If this documentary has a flaw, it's that it overestimates the attention span of the blogosphere—there was no need to revisit the Racism Scandal of Aught-Six, when blogger Jessica Hopper and the New Yorker's Sasha Frere-Jones accused Merritt of racism for not liking hiphop. (Frere-Jones appears in the film, apologizing forthrightly for his remarks.) But it's a minor hitch in what's otherwise an utterly worthwhile profile—frankly, two minutes of Merritt performing "Papa Was a Rodeo" are enough to justify the existence of the whole damn thing.