In “Resonance Alloy,” which the Either/Or ensemble presented at Miller Theatre in 2011, the composer Keeril Makan pulled off a small miracle: a half-hour-long piece for solo percussion that completely commands your attention. Its severely restricted collection of unpitched timbres (the player strikes a gong and three cymbals in an incessant stream of rhythm) has its antecedents in compositions by James Tenney and Alvin Lucier, but the work’s brave exploration of expressive territory makes it memorable. It’s lulling, thrilling, and, at times, downright eerie.