BATH — The Oratorio Chorale opens its 37th season with a program devoted to music of Bach and Duruflé, at 7:30 p.m., Saturday, Nov. 20 at United Church of Christ, Congress Avenue, Bath, and at 3 p.m., Sunday, Nov. 21. at Sacred Heart Church, Main Street, Yarmouth.

Director Peter Frewen –- who celebrates his 25th anniversary with the Oratorio Chorale this season — notes that these “two divergent composers separated by two centuries testify to the influential power of a 1,500-year tradition of western musical composition.” Both composers were renowned church organists who incorporated existing songs and melodies into their polyphonic music.

The works on the 90-minute program include Duruflés Requiem, Bach’s Cantata 23, and Bach’s organ prelude of Ein Feste Burg played by Ray Cornils, Municipal Organist for the City of Portland and Minister of Music at First Parish Church in Brunswick. The final piece on the program is the full performance of Bach’s Cantata 80, Ein’ feste Burg ist unser Gott.

Joining the chorale for this concert will be the Maine Chamber Ensemble and soloists, including soprano Christina Astrachan, mezzo-soprano Jennifer Hansen and bass/baritone John D. Adams. Astrachan has performed with the Portland Symphony Orchestra, Oratorio Chorale and Maine Music Society, among others. Hansen has performed throughout northern New England, specializing in oratorio and Bach roles. Adams has sung with the Oratorio Chorale, the Masterworks Chorale and has performed in opera, concert and recitals with orchestras and choruses in California and New England.

Tickets are $20 in advance, $25 at the door, half price for students, and free for children under 12. Tickets may be purchased from members of the chorale, at Gulf of Maine Books in Brunswick; Now You’re Cooking and Magnolia’s in Bath; Sherman’s Books and Stationery in Freeport; Clayton’s in Yarmouth; Books Etc. in Falmouth: Maine Coast Books in Damariscotta; Treats in Wiscasset; and Starbird Music and Longfellow Books in Portland.

For more information about this concert and the 2010-2011 season, visit www.oratoriochorale.org or call 725-1420.