Change appears to be coming, in some form or another, to Spectrum, the intimate Ludlow Street performance space that over the last five or so seasons has provided a home base for fascinating musical voyages spanning an unusually broad range of styles. Exactly what form that transformation might take has yet to be divulged, but one prospect seems clear: “In the last week of the Steinway D at Spectrum,” a recent Facebook event announcement stated plainly. Perhaps because of that hovering uncertainty, a pair of recent recitals by the pianists R. Andrew Lee and Sophia Subbayya Vastek seemed brushed with a sense of anticipatory valediction.

Maybe that’s premature: On April 5, Spectrum announced a May 12 performance of Messiaen’s Vingt regards sur l’Enfant-Jésus, for which a piano presumably will be present. And an element of closure was in some sense intrinsic to the program each pianist presented.

Lee, who flew in from Denver for his April 2 recital, opened with the work that (as he explained in a recent interview for The Log) initially inspired what quickly would become a noteworthy preoccupation with minimal music: The Time Curve Preludes, by the late American composer William Duckworth. Composed in 1977-78, the work is billed routinely as a watershed of post-minimalism – “music that takes its lead from the diatonic tonality and repetitive rhythms of Minimalism but deviates in matters of duration and style,” I wrote in a 2008 New York Times review of Bruce Brubaker playing portions of the same work at the Stone.

R. Andrew Lee at Spectrum, April 2, 2017

Like Brubaker (who was in the audience at Spectrum), Lee approaches The Time Curve Preludes with a winning mix of physical vitality and poetic sensibility. He molds phrases imaginatively with touch and pedal, bringing out whimsy, charm, and rusticity, while maintaining each prelude’s essential momentum. He applies the bass-note drones compelled by Duckworth’s score with subtlety and intelligence. As Lee played, you heard echoes and intimations of hymn tunes and Eastern modes, jazz and roots music, Debussy, Stravinsky, Messiaen, and more, interwoven in an organic matrix that unfailingly still sounds fresh.

Lee selected the other work on the program to acknowledge the more austere musical idioms for which he is most widely known. Certainly at its start, Inner Cities 8 by Alvin Curran fit the bill with its spare, gentle, isolated gestures. (Brubaker, too, had played Curran alongside Duckworth in 2008 – but there, rather than comparative quietude, Hope Street Tunnel Blues III offered a more frenetic show of energy.)

The music is austere yet allusive, spontaneous yet sure-footed, and filled with passages that sound faintly familiar – a bit of ruminative Beethoven here, mottled Morton Feldman chords there, a soft luminescence à la Arvo Pärt elsewhere. It all served to showcase Lee’s patience, even-handedness, and knack for continuity among disparate modes of expression, and provided a ruminative counterbalance to Duckworth’s more rigorously structured effusiveness.

Sophia Subbayya Vastek at Spectrum, April 4, 2017

Vastek, too, offered a variety of takes on minimal music in her April 4 recital, “Transition in Perception,” which she mounted in collaboration with the talented and industrious young composer Michael Vincent Waller – fixture of many a downtown event these last several seasons. But instead of works of extended duration, Vastek focused on miniatures: a notion that, Waller explained in his introductory comments, had arisen in a conversation he’d had with the composer Michael Byron.

From musical connections that surfaced in that exchange and others, Waller wove a gossamer web of brief, subtle pieces that followed in the footsteps of Satie and early Cage. The 75-minute program included 11 works, clustered in two shrewdly sequenced groupings.

Vastek opened with Byron’s As She Sleeps (2000) – a work strongly and sublimely redolent of Satie, and the first of several works that seemed to end mid-utterance rather than mustering some grand final flourish. The Canadian composer Linda Catlin Smith – whose profile has risen sharply over the last year thanks to exemplary recordings of her music issued by Another Timbre and Earwitness Editions – likewise looked to Satie in Poire (1994). Vastek’s left hand frequently wheeled and curled sympathetically in space while her right hand consorted instead with the sustain pedal.

Jo Kondo, a Japanese composer and Cage associate with whom Smith studied in British Columbia, offered stark, unsentimental chord progressions in High Window (1995), the results crystalline and finely faceted. Smith’s The View from Here (1992) hewed closer to Kondo’s planes of chords than had Poire, but with greater variety of gestures and motion. The first part of the program closed with Waller’s Early Night (2017): raga-inflected, picturesque, and more florid than anything that had come before.

After a brief pause during which Vastek prepared the piano’s innards, she opened the latter half of her program with Allison Cameron’s Corals of Valais (1997), a deceptively simple, quirky piece structured something like a slideshow: flashes of bright color framed by frequent, sharp silences. Cameron’s Chive Noses (2004), a world premiere, combined and reworked gestures from pieces by Schoenberg and Ives into a playfully aphoristic riddle.

Nick Storring, a compelling composer, cellist, journalist, and Canadian-music advocate based in Toronto, provided one of the evening’s highlights with Scarp (2017), another premiere. Opening with a staccato B-flat obsessively repeated, Storring vividly conjures a sparse landscape in economical strokes, dispensing color in daubs and sweeps; now and again some representative of Messiaen’s aviary might alight at the keyboard’s high end.

Michael Jon Fink, a California composer long linked to the eminent post-minimalist record label Cold Blue Music, emphasized simplicity and brevity in Two Etudes (1995-96) and Sunless (2014): the first a pair of evocations of a single mood apiece; the last, only slightly more elaborate, one of more than 120 pieces commissioned by Nicolas Horvath for a program honoring Philip Glass.

Closing the program, Waller’s Roman (2017) paid poignant tribute to the composer’s recently deceased father-in-law. Unabashedly heartfelt and sentimental, the music had more in common with Debussy, perhaps, than with anything that had preceded it here. This wasn’t the first time I’ve felt Waller’s music to be slightly at odds with the more experimental works he champions, but when faced with a composition as lovely and persuasive as this one, this hardly qualifies as a problem.

A wholly commendable enterprise, all told, and I now find myself eagerly anticipating Histories, Vastek’s upcoming recital disc of works by Cage, Michael Harrison, and Donnacha Dennehy (due May 26 on the Innova label). Both her event and Lee’s concert provided ample cause for concern over the potential loss of Spectrum as a home amendable to such intimate, thoughtful recitals – this despite the unavoidable incursion of car horns, conversations, and other noises seeping in from the street outside. One hopes fervently that a suitable solution arises to preserve this venue and safeguard the invaluable niche it fills.