Hamilton High chamber singers really cook in ‘Baked a Capella’

The vocal quartet Inner Voices has long been carrying the banner for a cappella -- or unaccompanied -- singing. On Sunday at the Baked Potato in Studio City, the group’s leader, Morgan Ames, took the campaign up a notch with “Baked a Capella,” a full evening of performances by Inner Voices, the Hamilton High School Chamber Singers and Deborah Dietrich (with Sheri Izzard and Susan Joyce).

The Hamilton ensemble, led by director John Hamilton, somehow managed to fill the venue’s tiny stage with more than 30 singers, but the real story with this extraordinary collection of young singers had more to do with quality than quantity. Performing with remarkable poise, subtlety and musicality, they sang a diverse program that included Renaissance counterpoint and contemporary dissonances. This is an ensemble that deserves a far wider hearing.

The Dietrich trio specializes in Eastern European music. Reminiscent of the Bulgarian women’s choir, their singing placed Dietrich’s flowing melismas and occasional exhortative shouts over grounded drone notes from Dietrich and Joyce. Other material -- especially an Israeli song -- suggested an impressive musical potential for this new ensemble, here making its debut.

As the headliner on the bill, Inner Voices (Ames, Shelby Flint, Melissa MacKay and Michael Mishaw) were, as always, precise and strikingly musical, especially in their set-closing tunes -- Joni Mitchell’s “Night Ride Home”; the “On Golden Pond” theme, “Where Am I Going” (music by Dave Grusin, lyrics by Ames); and the Annie Ross/Wardell Gray jazz gem, “Twisted.”

But the Inner Voices program -- which otherwise lacked the imaginative choices that made the Hamilton High and Dietrich trio sets so compelling -- never fully displayed the quartet’s brilliant technical and interpretive abilities.