Three Rivers Chorus will hold open rehearsals on Mondays, January 23 and 30, 7:00-9:15p.m., at the Knights of Columbus Hall, 52 Nason Street, Maynard. Auditions will follow immediately. Founded one year ago, the regional, mixed (SATB) Three Rivers Chorus champions the finest in ensemble singing to unite and strengthen the diverse communities along the Assabet, Sudbury, and Concord rivers. The chorus offers experienced singers a unique opportunity to bring the fullness of their voices and spirits together in varied and engaging repertoire where they can shine. The spring program includes River Songs by Gwyenth Walker; a jazzy choral suite by Jack Gottlieb; and pieces by Britten, Weelkes, Conte, and chorus member Ken Langer. Collaboration, improvisation, and audience participation are hallmarks of Artistic Director Ellen Oak's approach as she leads singers and audiences to connect the beauty and power of the music with their own daily lives.