Kronos gives Terry Riley a rapturous 80th birthday party

Hodges had sarcastically urged readers to “go ask a hippie” — and there was a bona fide hippie in the audience, enjoying the music and soaking up the adulation of the capacity crowd.

In the first movement of “The Cusp of Magic,” the quartet — Harrington and fellow violinist John Sherba, violist Hank Dutt and cellist Sunny Yang — were joined by the pipa virtuoso Wu Man for a stretch of music that began with a simple rhythmic pattern and then expanded to become a shaggy, enveloping groove, with hints of Delta blues and ripe Romanticism.

There were other celebratory gestures on the program as well, including a brilliantly moving solo by percussionist Zakir Hussain, the world premiere of a rambunctious dance by Polish composer Aleksander Kosciów, and Jacob Garchik’s gutsy quartet arrangement of Pete Townshend’s rock classic “Baba O’Riley.”

(As a special treat, the piece was announced by the disembodied voice of the great Studs Terkel, recorded during a live performance on Chicago radio station WFMT.) Hussain joined the quartet for the performance, and at the midpoint Wu Man made a reappearance to dive into the musical flow.

A host of performers who had been lurking like musical sleeper cells — including George Brooks, Gyan Riley, Jherek Bischoff, Mark Grey and more — stirred to life and joined in the festivities as the performance seemed to overflow its banks and fill the entire hall with good vibes.