After five years of regularly attending the Vision Festival, the annual week-long celebration of avantgarde and experimental music, I thought I had heard every possible kind of sound imaginable, from comparatively conventional horns and rhythm sections, to conch shells and shofars, to electronics. But I was completely unprepared for the sounds that greeted me as I ascended the stairs to the Angel Orensanz Center on Friday night: a full-size string orchestra that could have been playing either a symphony or a movie score.

This was “Fifty Violins for Leroy Jenkins,” a memorial salute for the pioneering free jazz violinist who passed away in February at the age of 74, assembled by Jason Kao Hwang and conducted by Billy Bang, two of Jenkins’s disciples. I couldn’t actually count the number of string players filling every centimeter of Angel Orensanz’s smallish stage, but they spanned the gamut from young student players to string celebrities such as Henry Grimes (here on violin) and at least a half-dozen bass fiddlers.

This brilliant 25-minute piece was created in the form known as “conduction,” perfected by composer Lawrence “Butch” Morris, in which not only the ensemble and pre-written portions but the improvisations are shaped by the director in collaboration with the individual players. Some sections were discordant and jarring, others were soothing and soaring, ranging from the free and atonal to more traditional “classical” European formal music.

This was just the first of several surprises on Friday: Next up came Roy Campbell’s Ahkenaten Suite, which brought back Mr. Bang as the other half of the front line, along with the bassist Hilliard Greene (who most of us know as longtime musical director for Little Jimmy Scott), drummer Zen Matsuura, and the vibraphonist Bryan Carrott in the role of the piano or chordal instrument.

I know Mr. Campbell to be one of the freest of free jazz trumpeters, as fine a representative of the form as is playing today, but this new work, receiving its world premiere at Vision, was anything but free. A largely pre-composed piece depicting Mr. Campbell’s vision of Africa both ancient and modern, it was warm and inviting, not to mention exotic and melodic in the most pleasurable way. The overall sound was like a Bobby Hutcherson Blue Note album circa 1965, combining elements of outside music with free-flowing late-bop against a Pan-African polyrhythm.

Using Mr. Bang’s violin as a secondary “horn,” Mr. Campbell softened his customary attack by using the harmon mute and switching to the mellower flugelhorn. “Ahkenaten” employed elements of dissonance and discord only as a seasoning, never as the main course.

The only performer on Friday night who did exactly what I expected him to — and for him, that’s more than enough — was the superior pianist Matthew Shipp. He played roughly the same kind of extended solo performance that I heard him do two months ago at Merkin Hall — an uninterrupted 40-minute set that juxtaposed a variety of approaches that could be described as both a set of rules and a personal style.

As on his most recent album, last year’s solo “One” (Thirsty Ear), Mr. Shipp made it clear that his music, even at its most dissonant and free-form, is always going somewhere. He uses classical compositional devices, such as reoccurring motifs and lots of contrast, as when he balances a series of jarring thuds in the left hand against a more melodic passage in the right. He also discreetly referenced piano forebears with sequences that were mysteriously Monkian, secretly Cecil-icious, or even like George Shearing playing Bach. As at Merkin, Mr. Shipp eventually made his way to the iconic standard “My Funny Valentine” as if demonstrating the evolution of music from chaos to Richard Rodgers, or from darkness to light in Genesis.

The two sets I heard Saturday were more in the vein of what one expects at Vision, starting with “Ganelin Trio Priority,” led by the keyboardist Vyacheslav Ganelin. His remarkable original Ganelin Trio, which co-starred the simultaneous multi-instrumentalist Vladimir Chekasin, was one of the most celebrated free jazz groups of the 1970s and ’80s. The current “Trio Priority,” which features Petras Vysniauskas on soprano saxophone and Klaus Kugel on piano, apparently made its New York debut this night.

After a brief piano introduction from the leader, the trio went right into the noisiest, loudest, and most cacophonic free music imaginable. When Mr. Ganelin pulled back from the extremest of extremes, as he did from time to time, it was possible to hear the beauty of the interplay between the three musicians, especially when Mr. Ganelin banged out rhythmic patterns in his left hand while playing the drums with his right; the effect of surrounding the soprano with two drummers produced some intriguing sounds. When he added electronic and synthesizer effects to the mix, it heightened the interest, but, unfortunately, the sheernoise quotient as well. At its most extreme, Mr. Ganelin’s music sounded like a 60-foot golem stomping on a shtetl.

Trumpeter Eddie Gale’s six-piece band only occasionally reached the outer fringes, and on the whole it employed a lot more contrast and musical variety; this was a logical outgrowth of the original free jazz that Mr. Gale helped pioneer in the ’60s with Sun Ra and Cecil Taylor. The sound is also similar to the music he recorded here two years ago for the recently released “Eddie Gale Now Band Live at Vision X featuring William Parker” (Voidleaper Productions), though the two saxophonists Mr. Gale employed this time around — Prince Lasha and Kidd Jordan — are both fellow vets of jazz’s original “October Revolution” of 40–45 years ago, and are considerably stronger.

Mr. Lasha varied between playing baritone sax in the ensembles and soprano in his solos, and also contributed a worthy ballad called “Take Time To Feel.” Apart from this romantic moment, the music of this outstanding sextet (which was joined by festival founder Patricia Nicholson, doing an interpretative dance) was by turns spiritual (in the opener, “Prayer for the World”) and political, as a lot of free jazz tends to be. Apart from Mr. Gale, whose rhythm section consisted of Valerie Mih on piano, Alvin Fielder on drums, and Mr. Parker again on bass, the star of the band was New Orleans’s most famous postmodernist, Mr. Jordan, who produced a wide variety of textures on his tenor and also shined brightly on the ballad, wherein he created a truly otherworldly sound on the horn.

Between the string orchestra, Roy Campbell’s Africana, and Mr. Shipp’s solo meditation, Friday was the most enjoyable night I’ve ever spent at Vision. What made it even more so, ironically, was the complaint of one wag I overheard as I was leaving the Angel Orensanz Center who griped that the sounds he heard weren’t far out enough to suit his tastes. This pundit apparently didn’t realize that for music to be truly free and open-ended, it has to accept the inside possibilities as well as the outside, the consonance as well as the discord, the beauty as well as the blast.

wfriedwald@nysun.com