This spring's big choral offering under John Adams' baton is the Brahms Requiem. One of the great settings of the mass for the dead, those who delight in large-scale sonorities will enjoy the Brahms.

A common complaint against chamber music, on the other side of the volume scale from nineteenth century masses, is that it is difficult to understand to the uninitiated. At Dunster House this week is an excellent chance to hear attractive, lighter works by Mozart and Poulenc. The players are some of the very best around Cambridge, among them Kathy Flanders (flute), John Eisenhart (horn), and Jay Gottlief (piano).

For the more hard-core sorts are the two Buswell-Carlin violin and piano recitals at Kirkland House. The music department's Lowell Lindgren has arranged a String Festival of Marlborough-caliber musicians. Other programs in the series will have cellists Madeline Foley and Yo-Yo Ma, violinist Annie Kavafian, and violist Marcus Thompson.

DUNSTER HOUSE LIBRARY. Vocal and string music composed and performed by Charles Kletzsch. April 20, 5:30 p.m.

ELIOT HOUSE LIBRARY. Sarah Brink, harpsichordist, in recital. April 20, 8:30 p.m.

SANDERS THEATER. Harvard-Radcliffe Collegium Musicum. Brahms: Requiem. Tickets: $5-$2. April 20, 8:30 p.m.

CABOT LIVING ROOM. Carol Magenau, soprano, and Gerald Moshell, piano. Song cycles by Schumann and Faure. April 21, 8:30 p.m.

DUNSTER HOUSE LIBRARY. Chamber music. Mozart: Flute Quarter in D; Poulenc: Sextet. April 22, 3:00 p.m.

MATHER HOUSE DINING ROOM. Emily Raymer, pianist, in recital. April 22, 3:00 p.m.

SANDERS THEATER. From Music Foundation concert. Leon Kirchner conducting a chamber orchestra with BSO players; soloists: Peter Serkin, Diana Hoagland. Free, no tickets. April 23, 8:30 p.m.

HAYNES CIVIC AUDITORIUM. Metropolitan Opera of New York. Carmen, Tosca, and II Trovatore presented April 23, 23, 25, at 8:00 p.m. Tickets: $17.50-$3.50; call KE6-5240.

PAINE HALL. Chamber music including Mahler: Kindertotenlieder (Jane Struss, alto); and Britten: Suite for Harp. Tickets $3 (Benefit for Nicaragua). April 24, 8:00 p.m.

KIRKLAND HOUSE. James Buswell IV, violin, and Seth Carlin, piano. Works by Bach, Beethoven, Dvorak, and Ravel. Tickets: $1. April 24, 8:30 p.m; Sonatas by Mozart. Tickets $1. April 25, 8:30 p.m.