The JACK Quartet has long seemed like a classical-music canary in a coal mine, veering into uncharted places that the larger public may not be ready for, but suggesting where the zeitgeist may be heading. That was particularly so at the Philadelphia Chamber Music Society concert on Friday at the Kimmel Center’s Perelman Theater, in which JACK collaborated with percussion virtuoso Colin Currie in a program that challenged what music can be.

Most extreme (but most fully realized) was the 2018 Everything Changes, Nothing Changes by Tyshawn Sorey, whose deeply experimental side might be a shock to those who know him only from Cycles of My Being, the song cycle he wrote for tenor Lawrence Brownlee. Played in a darkened auditorium, this string quartet work was uncompromisingly quiet, presenting a series of sonorities parceled out with deliberation, all similar in their outward manner but all built with subtle differences, the individual notes of the chords making staggered entrances with variations that somehow demanded to be perceived. You were either asleep or transfixed.

I was in the latter category, partly thanks to having points of reference with Sorey’s now-deceased 20th-century antecedents, Morton Feldman and Luigi Nono, whose precedents didn’t make Sorey less radical. Though it can be found on recordings, his piece is a singular experience that really needs to be encountered live. JACK’s concentration was so intense that the overall effect was that of a sensory deprivation tank, and was intelligently positioned in the program just before the concert’s most exuberant piece, Steve Martland’s 2008 Starry Night for percussion and string quartet, which made that much stronger an impression, having been heralded with such quietude.

This was the oldest piece in the program, and the sooner you forgot about the title’s Vincent Van Gogh reference, the better. A continuous stream of music that beautifully integrates strings and percussion, Starry Night started out almost as a series of traditional movements — with quartet joined later by percussion — in that same machine-tooled style of British minimalism as practiced by Michael Nyman. However, everything started to melt together with pithy minimalist motifs that evolved into something resembling pop-music song hooks. Cool mechanics gave way to inhibited joy.

The youngest piece on the concert was completed this past Tuesday. No wonder there were no printed program notes. But nothing about Andy Akiho’s Aluminous or its performance felt last-minute — and that’s a hallmark of JACK, which not only plays challenging music well but seems to fully fathom it. The music had a wonderful way of gathering momentum, only to have individual strands in the quartet stumbling all over each other. The percussion writing was like a music box careening toward a psychotic breakdown. Pizzicato string writing recalled Tchaikovsky’s Symphony No. 4 on steroids. Aluminous made me very happy to live in an age when all such things can co-exist in the same piece.

Most new music programs are going to have something you don’t connect with. Rolf Wallin’s Realismos magicos, written for percussion, had Currie playing marimba in a series of haiku-like micro-movements inspired by the writings of magic-realist novelist Gabriel García Márquez. As much as I love Márquez, the movement subtitles weren’t so evocative and the music itself was often so terse you had little to latch onto. Rather annoying.

Suzanne Farrin’s 2018 Hypersea for quartet and percussion also eluded me, but not for lack of content. The piece amplifies theories on the fundamental characteristics of water as codified by scientists Mark and Dianna McMenamin — fascinating! — with a succession of exclamatory gestures suggesting nascent forms of life. But I’m at a loss to say how or if the pieces added up.

Sometimes musical understanding evolves along with the terminology for explaining it. While previewing Farrin and Sorey on YouTube in the afternoon before the concert, I tried explaining to some plumbers working in my apartment what set these sounds apart from, say, a smoke alarm. Partly, it’s a sense of musical organization, and Sorey has that. But beyond that, this is the best I could do: “It’s like the world really is flat, and you’re standing on the edge with no reference for what you see below ... .”