“Everything Changes, Nothing Changes”: Tyshawn Sorey wrote the string quartet that bears that title in 2018. But the sentiment is so tailor-made for the past year that when the JACK Quartet announced it would stream a performance of the work in December, I briefly forgot and assumed it was a premiere, created for these tumultuous yet static times.

I should have known better. Mr. Sorey already had enough on his plate without cooking up a new quartet. The final two months of 2020 alone brought the premieres of a pair of concerto-ish works, one for violin and one for cello, as well as a fresh iteration of “Autoschediasms,” his series of conducted ensemble improvisations, with Alarm Will Sound.

That wasn’t all that happened for him since November. Mills College, where Mr. Sorey is composer in residence, streamed his solo piano set. Opera Philadelphia filmed a stark black-and-white version of his song sequence “Cycles of My Being,” about Black masculinity and racial hatred. JACK did “Everything Changes” for the Library of Congress, alongside the violin solo “For Conrad Tao.” Da Camera, of Houston, put online a 2016 performance of “Perle Noire,” a tribute to Josephine Baker that Mr. Sorey arranged with the soprano Julia Bullock. His most recent album, “Unfiltered,” was released early in March, days before lockdown.

He was the composer of the year.

That’s both coincidental — some of this burst of work was planned long ago — and not. Mr. Sorey has been on everyone’s radar at least since winning a MacArthur “genius” grant in 2017, but the shock to the performing arts since late winter brought him suddenly to the fore as an artist at the nexus of the music industry’s artistic and social concerns.

Undefinable, he is appealing to almost everyone. He works at the blurry and productive boundary of improvised (“jazz”) and notated (“classical”) music, a composer who is also a performer. He is valuable to ensembles and institutions because of his versatility — he can do somber solos as well as large-scale vocal works. And he is Black, at a time when those ensembles and institutions are desperate to belatedly address the racial representation in their programming.

He’s in such demand, and has had so much success, that the trolls have come for him, dragging him on Facebook for the over-the-topness of the biography on his website. (Admittedly, it is a bit adjective-heavy: “celebrated for his incomparable virtuosity, effortless mastery,” etc.)

The style for which he has been best known since his 2007 album “That/Not,” his debut release as a bandleader, owes much to the composer Morton Feldman (1926-87): spare, spacious, glacially paced, often quiet yet often ominous, focusing the listener purely on the music’s unfolding. Mr. Sorey has called this vision that of an “imaginary landscape where pretty much nothing exists.”

There is a direct line connecting “Permutations for Solo Piano,” a 43-minute study in serene resonance on that 2007 album, and the first of the two improvised solos in his recent Mills recital, filmed on an upright piano at his home. Even the far briefer second solo, more frenetic and bright, seems at the end to want to settle back into gloomy shadows.

“Everything Changes, Nothing Changes,” a hovering, lightly dissonant 27-minute gauze, is in this vein, as is the new work for violin and orchestra, “For Marcos Balter,” premiered on Nov. 7 by Jennifer Koh and the Detroit Symphony Orchestra. Mr. Sorey insists in a program note that this is a “non-certo,” without a traditional concerto’s overt virtuosity, contrasting tempos or vivid interplay between soloist and ensemble.

“For Marcos Balter” is even-keeled, steadily slow, a commune of players rather than a metaphorical give-and-take between an individual and society. Ms. Koh’s deliberate long tones, like cautious exhalations, are met with spectral effects on the marimba. Quiet piano chords amplify quiet string chords. At the end, a timpani roll is muted to sound almost gonglike, with Ms. Koh’s violin a coppery tremble above it.

It is pristine and elegant, but I prefer Mr. Sorey’s new cello-and-orchestra piece, “For Roscoe Mitchell,” premiered on Nov. 19 by Seth Parker Woods and the Seattle Symphony. There is more tension here between discreet, uneasy minimalism and an impulse toward lushness, fullness — more tension between the soloist receding and speaking his mind.

The piece is less pristine than “For Marcos Balter,” and more restless. The ensemble backdrop is crystalline, misty sighs, while the solo cello line expands into melancholy arias without words; sometimes the tone is passionate, dark-hued nocturne, sometimes ethereal lullaby. “For Roscoe Mitchell” feels like a composer challenging himself while expressing himself confidently — testing the balance of introversion and extroversion, privacy and exposure.

But it’s not right to make it seem like an outlier in this respect; Mr. Sorey’s music has never been solely Feldmanian stillness. In Alarm Will Sound’s inspiringly well executed virtual performance of “Autoschediasms,” Mr. Sorey conducted 17 players in five states over video chat, calm at his desk as he wrote symbols on cards and held them up to the camera, an obscure silent language that resulted in a low buzz of noise, varying in texture, and then, excitingly, a spacey, oozy section marked by keening bassoon tones.

And he isn’t afraid of pushing into a kind of Neo-Romantic vibe. “Cycles of My Being,” featuring the tenor Lawrence Brownlee and texts by the poet Terrance Hayes, nods to the ardently declarative mid-20th-century American art songs of Samuel Barber and Lee Hoiby, just as “Perle Noire” features, near the end, a sweetly mournful instrumental hymn out of Copland.

“Cycles,” which felt turgid when I heard it in a voice-and-piano version three years ago, bloomed in Opera Philadelphia’s presentation of the original instrumentation, which adds a couple of energizing strings and a wailing clarinet. And after a year of protests, what seemed in 2018 like stiffness — in both texts and music — now seems more implacable strength. (Opera Philadelphia presents yet another Sorey premiere, “Save the Boys,” with the countertenor John Holiday, on Feb. 12.)

“Perle Noire” still strikes me as the best of Sorey. Turning Josephine Baker’s lively numbers into unresolved meditations, here is both suave, jazzy swing and glacial expanse, an exploration of race and identity that is ultimately undecided — a mood of endless disappointment and endless wishing. (“My father, how long,” Ms. Bullock intones again and again near the end.)

In works this strong, the extravagant praise for which some have ribbed Mr. Sorey on social media — that biography, for one, or the JACK Quartet lauding “the knife’s-edge precision of Sorey’s chess-master mind” — feels justified. And, anyway, isn’t it a relief to talk about a 40-year-old composer with the immoderate enthusiasm we generally reserve for the pillars of the classical canon?