The Ecstatic Music Festival at Merkin Concert Hall Ecstatic Music Festival: The composer Dan Deacon, center, with the violist Jonathan Moerschel and the cellist Eric Byers of the Calder Quartet at Merkin Concert Hall on Tuesday evening. Collaboration, the odder the better, is the engine that drives the Ecstatic Music Festival at Merkin Concert Hall. You can think of Judd Greenstein, the composer who assembles its programs, as a mischievous matchmaker who dreams up blind dates that seem as likely to create sparks as to create harmony. Mr. Greenstein must have been feeling especially daring when he drew up the program for Tuesday evening. The first half offered separate performances by the Now Ensemble, a hybrid chamber group and jazz-rock band, and the Calder Quartet, which is known for a repertory that includes both standard string quartets and adventurous new works. The two groups were then yoked together for a piece by the electronic music composer Dan Deacon, who sat off to the side, controlling a laptop packed with aggressive sounds and a rambunctious Yamaha Disklavier, the modern digital equivalent of a player piano. Mr. Deacon's work, "An Opal Toad With Obsidian Eyes" (2012), was the clear draw here and the biggest question mark. Mr. Deacon is best known for purely electronic works in a style that veers from the texturally transparent and whimsical to dense, frenetic blends of indie rock and Minimalism. When he has written for musicians, as he did for last year's festival, composing a piece for So Percussion, his music has focused on rhythm and timbre rather than on the combinations of pitches and interplay of themes that you might expect in a work for strings, woodwinds and piano. For a while, Mr. Deacon's piece was an arresting study in glacial morphing: in its opening movement, "Mirkwood Drone," a loud, steady electronic buzz grew more complex as Mr. Deacon played with its overtones, and as the musicians matched pitches within the increasingly dense, abrasive chord. Rhythm, defined by a steady, pounding pulse - first from Mr. Deacon's computer, then from Michael Mizrahi, the Now Ensemble's pianist - defined the second movement, "Fleece Needs," with the players building a texture that had both the intricacy of a watch mechanism and the brutal force of a turbine engine. In the finale, "Caddyshack Batman," Mr. Deacon began to meander. A long section for the Disklavier, programmed to play a jangly, chattering passage that seemed to use all of the instrument's keys, gave way to stretches of ensemble texture that seemed loosely patched together, and as the piece approached the hour mark, it began to wear out its welcome. The works on the first part of the program were more compact. Mark Dancigers, the Now Ensemble's guitarist, contributed "Cloudbank" (2006), a blend of attractive thematic bursts that mixes post-tonal modernism and jazz-tinged woodwind lines, and grows gradually more expansive. And Daniel Wohl's "Glitch" (2009), a busily tactile essay for strings and electronics, demanded a virtuosic wildness that the Calder Quartet supplied unwaveringly. The Ecstatic Music Festival runs through Wednesday at Merkin Concert Hall, 129 West 67th Street, Manhattan; (212) 501-3330, kaufman-center.org.