When he's not onstage playing a show, you'll likely find Evan Mast puttering around his apartment with a microphone, tossing sneakers against the wall

When he's not onstage playing a show, you'll likely find Evan Mast puttering around his apartment with a microphone, tossing sneakers against the wall or tapping on different surfaces, trying to capture the perfect percussion effect. It's that sort of recording ingenuity that marks the sound of Ratatat, an unorthodox collaboration between Mast, a career knob-twiddler, and guitarist Mike Stroud.

Classics, their latest effort on XL Recordings, is pregnant with homemade and found sounds, though Ratatat's music leans with equal weight on an arena-rock style and on pushing a guitar's sound beyond convention. (Think Brian May of Queen, who built a guitar to suit his needs; and Robert Fripp, a guitarist known for his innovative studio recording techniques.) As a pair, Mast and Stroud fuse the hair-thrashing incentive of dueling-guitar rock with broken-beat drum patterning.

Since releasing its self-titled debut (also on XL) two years ago, the duo has split time between touring and recording. The recording part had its stressful moments. “We had tons of bad starts,” Stroud admits. “We had so many half-finished songs that didn't go anywhere. I think that's partly what caused the length of time [it took to record]. We were like, ‘What's going on? These songs suck!’ But we managed to break through that at one point, and then we just got momentum.”

The tracks they didn't trash got filed in a data folder marked “Classics” — a little inside-joke that later spawned the name of the album. Though they admit their creative process is pretty much hit or miss and the layered approach they take can be exhaustive, neither partner can imagine working any other way.

“Each song is usually a pretty long process of weeks or even months of going back and forth,” explains Mast. “We get very detailed, polishing different elements and trying to pull other elements out. We do a lot of redoing sounds. We write a melody and try it out on a couple different instruments and see how the sound works best.”

Oftentimes, straightforward instrumentation will simply not do the trick. A favorite of Mast and Stroud's methods is to employ a backward guitar effect: They'll write a chord progression or melody, play it backward on guitar (if the progression is, for example, ABCD, they'll play it as DCBA) and then reverse the recording for the final effect.

“It sounds normal when you're playing it — usually it just sounds kind of like a really bad part — but then once it's reversed, it's the right notes, and it's just a weird sound,” Mast says. “It's like these notes that start quiet and then get bigger as they go.”

“We use guitar for almost everything,” adds Stroud, who plays a '65 Epiphone Wilshire. “There are some organs, but lots of the weird stuff you hear that you'd think are keyboards are really backward guitars. We just try to get the most interesting sound. We'll use a keyboard part, and we always end up thinking, ‘This would probably sound cooler on a backward guitar.’”

The duo's first album, Ratatat, was recorded in Mast's self-described tiny bedroom, every instrument recorded on a laptop. “We recorded everything directly through a distortion pedal, so all the sounds became very small,” Mast says. “Because we had the same path for every sound, the guitars ended up sounding like the keyboards, and it kind of gave it a very particular constraint, which I think works for some of it.” This time around, they added a guitar amp and mic, and they did away with guitar loops. “I just played throughout the entire [song] so you hear more subtlety, little changes,” Stroud says.

Since the particulars of their recording techniques are virtually impossible to re-create live, Stroud uses an EBow at shows. “[Because] it makes your strings vibrate without picking the guitar, it sounds sort of backward, like an endless note,” he says. Also, because many of the tracks involve some 20 layered guitar parts, Ratatat enlisted an organist live, and Mast also plays guitar.

“We never considered playing live at all when we were making the first record,” Stroud recalls. “If we're headlining, a song will come on, and the crowd starts cheering because they know it. But if we're opening for someone, it's definitely hard — they've never heard us before, there's no singer, and it's just two guys onstage, but there's all this music. It's a little weird. They're probably just like, ‘What is this? What's going on?’”