With its current concerts, titled "Metamorphosis," Cantus celebrates the coming of spring (or at least the hope of it) with a program built around ideas of rebirth, renewal and transformation. The program is as diverse and eclectic as the tastes of the male choral group's nine members.

With 21 selections, they cover a great deal of territory. But what Cantus really excels at is the sequencing of the pieces. They gain meaning through their juxtaposition.

The program doesn't stint on classical music. There are medieval and Renaissance pieces, like the 15th-century French Easter carol "Now the Green Blade Rises," the witty Renaissance piece "El Grillo" by Josquin Des Prez and the 16th-century English tune,"Now Is the Month of Maying," by Thomas Morley.

There are 19th-century choruses by Schumann and Strauss and, especially effective, "Lift Thine Eyes" from Mendelssohn's "Elijah." And there are contemporary art songs. "Things I Didn't Know I Loved," by Cantus member Timothy C. Takach, is a passionate setting of a man re-experiencing the world after years in a Russian prison, sung with an exceptional love.

"The Turning," by Maura Bosch, sets works of men in an anger-management class.

Throughout this formal section of the program, the men are stylistically and technically assured. But they still sing with passion and exuberance.

Much of the program is a survey of folk music. With Irish, Norwegian and Estonian folk songs, Cantus captures the artless, unsophisticated nature of the tunes.

These serious musicians don't take themselves too seriously. "Legenda," by Einojuhani Rautavaara, elicits a tongue-in-cheek reading of a witty Finnish conversation between God and St. Peter.

The sense of transformation is not only described in the texts of the songs. The way the ensemble performs them is transformational in itself. The concert begins with the familiar "Morning Has Broken," opening with a tenor solo over ethereal chords that proves haunting.

As winter lingers, seemingly endlessly, this program offers hope and joy, a balm to the ear — and to the spirit, as well.

William Randall Beard writes about music.