About five minutes before the end of John Cage’s “Music of Changes,” which pianist Joseph Kubera performed in the opening concert at this year’s Summer Institute of Contemporary Performance Practice, the notes stop, the silence that punctuates the work’s 45 minutes seems to win out. But more notes come. It’s not the end, not even a false ending. The score’s consistent variability insists that there’s nothing false, or even true, about such a gesture. Musical shape is an illusion; the experience of it is the only sure thing.

For SICPP — a week for students to immerse themselves in the avant-garde, hosted by the New England Conservatory, directed by pianist Stephen Drury — focusing on Cage’s centenary and his influence emphasizes the “practice” in its name, the music entailing not only performance practice at oblique angles to tradition, but mental practice that retools the conception of music itself.

And even when not very contemporary (everything on Sunday’s faculty concert was over 50 years old), the practice still feels radical. The 1957 three-piano “Sonata” by Christian Wolff, this year’s SICPP composer-in-residence, gives rules rather than explicit instructions for filling up blocks of time with musical objects. Attention shifts to the choices the players make, the way they do or don’t respond to the choices of the others. Performed by Drury, Yukiko Takagi, and Steffen Schleiermacher, the “Sonata” felt purposeful, formal, even as sudden bursts of volume or surprising prepared-piano sounds preempted symmetry.

Cage’s “Winter Music,” also from 1957, is even more freeform, anywhere from one to 20 pianists able to arrange any amount of the music in any order. And yet the experience was consilient, as performed by Schleiermacher and Louis Goldstein, two of this summer’s guest artists — an inventory of sharply polished, lush beauty, tolling sound by sound.

“Music of Changes,” from 1951, was Cage’s first completely chance-generated piece, with musical materials fixed to the page in formidable detail, a painstaking record of random events. Long and often dense with flourish — single-note fusillades, glissandi, clusters, gradually expanding into the strings and even the lid and case of the instrument — it’s a test of technique and concentration.

Kubera, a longtime advocate, more than met the challenge. His bravura command made “Music of Changes” feel as monumental as, say, a late Beethoven sonata. But it’s also the opposite, music as nothing but its own realization, purified of any rhetorical hierarchy. The human urge to impose order is strong, but in “Music of Changes,” sheer providence reveals a virtuosity all its own.