Ten extraordinary years in about 16 minutes.

That's how conductor Donald Nally described the opening of the Crossing's concert - the first in this terrific chamber choir's 10th-anniversary season - on Sunday at the Presbyterian Church of Chestnut Hill.

The program began with the first work the Crossing sang in public, on Nov. 8, 2005. Gabriel Jackson's A Prayer for Peace isn't easy, exactly, but it is simple: a plaintive, sinuous unison line for sopranos over organ chords - fitting for what was then a small group of old friends who missed each other and wanted to sing together.

Fast-forward to the Crossing's newest commission: composer Stratis Minakakis' harrowing Crossings, inspired by the sight of thousands of desperate Syrian refugees streaming onto a Greek island. Eighteen separate voices sighed, whispered, whistled, hummed, ululated, and generally shattered a text of 20 words from T.S. Eliot's The Waste Land. It wasn't beautiful - it wasn't meant to be - but it was powerful, and it showed the astounding level of skill and commitment that Nally and his singers have reached over their decade together.

The rest of the program - reprising some of the group's favorite pieces from previous seasons - showcased the Crossing's strengths: excellent blend and tuning; crystalline tone; the ability to handle languages from English to German to Albanian; and a sharp eye and ear for new music that's intelligent, emotionally compelling, and, often, simply beautiful. (Their one weakness, to my ear - sometimes unclear diction - was in evidence, but that hardly took away from the overall effect.)

Those pieces were Eriks Esenvalds' Legend of the Walled-In Woman, haunting, rustic keening inspired by a grim old Albanian folktale; Jackson's According to Seneca, a soulfully meandering meditation on the wind blowing off the sea; Paul Fowler's Breath, an atmospheric setting of a bleak Philip Levine poem; and Robert Maggio's The Woman Where We Are Living, a brilliantly innovative - and even, in its way, consoling - cycle of excerpts from the journals of Alois Alzheimer about the first patient to be diagnosed with the disease that bears his name.