The Alaska Chamber Singers, with musical director David Hagen, present “Darwin Sings: The Evolution of Choral Music” at 7 p.m. Saturday at the Mariner Theatre. The Homer High School Concert Choir makes a special appearance. The concert explores the history of Western choral music from chant and organum of the Dark Ages through the Renaissance, Baroque, Classical and Romantic eras and into the 20th century and beyond. Tickets are $12 adults, $10 seniors and $7 students with proceeds benefitting the Homer High School Concert Choir.