Radius Ensemble (radiusensemble.org) opens at Longy Oct. 5 with music of Rota, Piazzolla and Luna Pearl Woolf, the first of four concerts at the Cambridge conservatory that all begin with Radius’ unique brand of casual introductions. A Nov. 23 program mixes a premiere by John Holland with works by Martinu and Dvorak; on Mar. 8, Chen Yi shares the bill with Mozart and Bartok; on May 3, Evan Ziporyn joins musical forces with Lalo Schifrin and Debussy.

By: Keith Powers