If the experience of listening to music has become an increasingly insular occasion of individuals floating inside the private bubbles of their iPods, then there also exists a movement toward the other end of the spectrum: the concert as a mass public immersion in a tribal sonic ritual.

And, no, not at Bonnaroo or Burning Man. Try the banks of the East River in Williamsburg or Damrosch Park at Lincoln Center, both of which will host unique events this weekend and next at which scores of musicians will congregate to create transcendent noise with a single instrument.

The numerically obsessed concert known as 88 BoaDrum summons 88 drummers to the Williamsburg Waterfront (N. 8th Street and Kent Avenue) at 8:08 p.m. for an 88-minute performance on Friday, which is, of course, abbreviated as 8/8/08. The performance is a sequel to last summer’s 77 BoaDrum, a concept invented by the Japanese noise rock band the Boredoms and their frontman-shaman Yamantaka Eye. Upping the ante this year, and with corporate sponsorship from Nike, the Boredoms will convene a West Coast version in Los Angeles’s La Brea Tar Pits, while the Brooklyn rock band Gang Gang Dance will take charge of the Williamsburg performance.

In a completely unrelated happening, the guitarist and composer Rhys Chatham will conduct 200 electric guitarists as part of the Lincoln Center Out of Doors festival. The August 15 concert follows similar convergences earlier this year in Williamsport, Pa., and on infrequent occasions since Mr. Chatham premiered his first 100-guitar composition, “An Angel Moves Too Fast To See,” in 1989.

“There’s a huge laying out of the ego,” one participant in 88 BoaDrum, Ryan Sawyer, said. The drummer, who plays in the band Tall Firs and has collaborated with such icons of New York’s musical underground as Sonic Youth founder Thurston Moore and saxophonist Charles Gayle, will be the first percussionist in the spiraling formation that defines 88 BoaDrum. Some of his associates will include members of notable indie-rock acts such as Chavez, Modest Mouse, Parts & Labor, God Is My Co-Pilot, Metric, and TV on the Radio. “It’s very community oriented. It’s a major effort to get this many people organized to do something. The first one was legendary even right after it happened.”

The spiral progression of the piece, which is cued by various drum captains holding color-coded staffs, creates what Mr. Sawyer calls an “energy field” that flows out of the repetitive percussive patterns created by the domino-like array of drummers — each of whom plays a full drum kit. The effect is cumulative, and galvanizing for the audience, which is meant to complete and extend the spiral. “Everyone’s enthusiasm is viable,” Mr. Sawyer said. “For two weeks after [77 BoaDrum], there were complete strangers stopping me and hugging me on the street.”

Something similar happens in the wake of performances by Mr. Chatham’s guitar armies, which are recruited for his site-specific concerts in different cities around the world.

“After the week of rehearsals, there were always two or three new bands that formed as a result of musicians meeting each other in this context,” the composer, who was a pivotal part of the downtown New York music scene in the 1970s and ’80s, said in an e-mail from his home in France. “It was beautiful to see everyone getting together and sharing ideas and simply talking and having fun. We become a small community; we eat together, we pray together, and we play together.”

The piece to be performed by the 200 guitarists (plus 16 bassists), “A Crimson Grail (Outdoor Version),” is a “leaner and meaner” variation on the 2005 “A Crimson Grail (For 400 Electric Guitars),” which premiered in the Sacré-Coeur in Paris as part of La Nuit Blanche Festival. For the original piece, Mr. Chatham had to account for the 15-second reverberations caused by the cathedral’s 272-foot-high ceiling. Far from a latter-day evocation of Eric Burdon’s fantasy of “10,000 guitars, grooving real loud,” expressed in the 1967 hit “Monterey,” the music might well be sanctified smoke rising from a chalice.

“I really know the sound and the sonority of a massing of guitars this size,” Mr. Chatham said. “Of course, there are thunderous moments, but I must say, there is nothing like the sound of 100, 200, 400 guitars playing quietly. It’s fantastic, there’s nothing to compare to it. ‘A Crimson Grail’ is not about raw power and rock ‘n’ roll. It is about the sacred ritual of 216 musicians getting together to offer up a loving sacrifice to the moon goddess. It’s about the sound of 200 guitars playing quietly. It’s about refinement.”

Robert Poss, a New York-based guitarist who worked with Mr. Chatham in the 1980s and rejoins the composer as one of the throng playing “Die Donnergotter,” recalled a year-plus worth of effort that went into the creation of one of Mr. Chatham’s classic pieces, “Guitar Trio.”

“There was a real architectural beauty to it,” Mr. Poss said. “It’s a total landscape. Sometimes, with more guitars, the less you get. You can dilute what’s happening.” Instead, part of Mr. Chatham’s gift as a composer and collaborative artist is his ability to conjure “a sonic cloud that is a really beautiful thing.”

Mr. Poss, a founder of the art rock outfit Band of Susans, will play alongside veteran associates of Mr. Chatham, such as Ned Sublette and John King, as well as guitarists Seth Olinsky (Akron/Family) and David Daniell (of Mr. Chatham’s band Essentialist) — part of a new generation of players who have embraced the Mr. Chatham’s rock-infused minimalism.

Aesthetic concepts aside, Mr. Chatham emphasized the core experience. “It’s also about 216 people getting together to have a rock-roaring time,” he said. The same sentiment holds for this week’s 88 BoaDrum. “You can feel the presence across your whole body of everyone doing it,” a Brooklyn-based drummer who participated in the 2007 event, Jim Black, said. “Sometimes, you just want to punch through the brick wall. I destroyed three drum heads on that gig. And I have good technique.”