Dither is a New York-based guitar quartet, unusual in that the four guitars are electric and much of the music performed here is through-composed, including verbal and graphic scores. It’s unusual, too, in maintaining much of the traditional split between composers and interpretive performers. There are five composers represented here and only one, Joshua Lopes, is actually a member of Dither, otherwise made up of Taylor Levine, David Linaburg and James Moore. It’s an oddly formal distinction, for the performances can reach levels of volume and insistence that are usually reached without a program. The CD opens and closes with aural shock treatment. After a quiet lacework of isolated harmonics and hum, Lainie Fefferman’s “Crown of Thorns” suddenly turns to a crushing repeated chord that suggests the Velvet Underground, or even loops of the Velvet Underground, humming feedback and overtones providing variety. The conclusion, Erik km Clark’s “exPat,” is even more provocative, a hearing deprivation piece in which the four guitarists play the same music while wearing headphones that blast white noise, making it impossible to hear one another. In between, though, there are more immediately engaging moments as the group collaborates with composers to explore the electric guitar’s range of tunings and textures, often contrasting rock-inspired skronk with a subtle control of quarter- tones. The CD’s most compelling moments come in Lisa R. Coons “Cross-sections,” a four-part, 24-minute work that begins with broken rhythms that can suggest Captain Beefheart & the Magic Band and the surf band staple “Bumble-Boogie,” only to extend to a long segment called “Prolix” that demonstrates Dither’s remarkable abilities to match high levels of control and complexity. It’s an intriguing debut by a group that summarizes much of the electric guitar’s history (from Dick Dale to Fred Frith) and mines further possibilities of their own.