"Dear MFA,Please buy some new audio equipment.

Love, Andrea."

This was the introduction I wrote upon leaving the Museum of Fine Arts on Friday night after the first of the Mountain Goats' two area-shows last weekend. The museum is no stranger to rock concerts; such indie rock luminaries as the Dirty Projectors (who will be performing here at Cholmondeley's later this month) and the Blow have performed there in the last several months. One would not expect a venue that often hosts indie rock shows to be so ill-equipped. One would be grossly mistaken.

You know that blunt, hollow feedback sound that comes from holding a guitar too close to an amp? It sounds approximately like this: hhnnnnnNNNNhhhhrrrrrr. Instead of delicate strings or keyboard figures, the Mountain Goats' songs were overlaid with a thick swath of feedback.

The Mountain Goats themselves were overlaid with some strange lighting effects. The lights appeared to be directly above the members of the band, shining vertically down on the musicians and giving their faces a campfire scary story look. Colored lights along the ceiling at the back of the stage shone on the drummer, creating further visual strangeness. One might expect the MFA to have more artistic (or at least more effective) lighting design-after all, what institution is more concerned with aesthetics than a museum? However, one would again be grossly mistaken.

Combine these two very obvious deficiencies with the distinct lack of energy at the venue (one concertgoer described it as "high school auditorium") and with what I assume to be the band's preconceptions of performing in an art museum, and the result was a very strange experience indeed.

Perhaps the strangeness worked to the advantage of the opening act, the Moaners, from Chapel Hill, NC. The band, consisting of a female singer and guitarist and a female drummer, sounded larger than it was. I was surprised to enter the theater and see what I'd been hearing from the lobby. Although its loud Texas blues-rock was a little underwhelming, the group ended with a saw solo, which never fails to impress a crowd. Maybe the weirdness of the MFA-as-rock-venue also precipitated this strange but entertaining exchange onstage between songs:

Melissa Swingle, guitarist: "I don't know if you'll notice this, but [the Mountain Goats] all have the biggest feet I've ever seen."

Laura King, drummer: "Huge. I don't know how they get in the van."

The following night, at the Middle East downstairs, the atmosphere (and the club's audio equipment, one must assume) was completely different. The Moaners played a short set of similar songs with little experimentation or banter. Not that I particularly relished their Friday night performance, but on Saturday, by the second song I'd had enough of the slide guitar. Too much sliding evokes the sound of heavy machinery trying repeatedly to power up.

The Mountain Goats' set, on the other hand, was infinitely more enjoyable at the Middle East. I think the club atmosphere was a large part of it-compared to the MFA crowd, the Cambridge audience seemed younger, more informal and more excited to have waited three and a half hours after doors opened to see a band that has no trouble selling out the venue every several months.

With a capable sound system and a more at-ease audience, the band played a set consisting of songs from a variety of different phases in singer John Darnielle's long career. At the Friday show, the set consisted almost entirely of songs from the new album released last month, Heretic Pride, and from The Sunset Tree (2005), which most critics consider one of their most successful albums. On Saturday, however, Darnielle treated the fanatical audience to tracks from his first 12-inch as well as the much-requested "Going to Georgia" from Zopilote Machine (2005) and, during the second encore, the fan-favorite "The Best Ever Death Metal Band in Denton" from All Hail West Texas (2002).

One aspect of Saturday night's show that may have rankled hardcore fans was the presence of a drummer onstage. Jon Wurster, who previously was a member of Superchunk, plays drums on the latest album and is touring with the Mountain Goats--a group that for years has consisted only of Darnielle and bassist Peter Hughes-for the first time this spring.

"People aren't used to it," Wurster said in an interview with the Justice before Friday's show. Concertgoers have "a preconceived notion . they're used to seeing two guys on stage, [and now] they see three guys on stage," he said. At both shows, Wurster's performance was top-notch; he was both very skilled and very engaged throughout. Still, I'm not sure I entirely liked the addition of a third instrument on stage. Wurster was a treat to see by virtue of his skill, making his two performances perhaps the lone consistency between the two shows. After a year and a half of concertgoing in Boston and with the Mountain Goats' two performances acting as a control variable, I can say with ever-increasing certainty that the Middle East is head and shoulders above Boston's other rock venues.