Both of the undergraduate orchestras have concerts this weekend. The HRO will feature violinist Lynn Chang in the demanding Sibellus Concerto. Brahms Fourth is also on the program for a full dose of late Romanticism.

If French impressionism is more to your taste, the Bach Society is presenting an all-Ravel concert in honor of his one hundredth birthday. Neal Stulberg will be the Soloist in the infrequently heard Plane Concerto in G, a work which shows where Ravel's student Gershwin Picked up a few of his tricks. Friday:

Sibellus Violin Concerto, Brahms Symphony #4, and Ruggles Men and Mountains: Harvard-Radcliffe Orchestra, James Yannatos, conductor, Lynn Chang, violin soloist; Sanders; 8:30.

Two Mozart Plano Sonatas: John Kirkwood; Dunster Library; 5:30.

Saturday:

All-Ravel Concert including Tombeau de Couperin, Mother Goose Ballet, Pavane for a Dead Princess, and Plano Concerto in G; Hugh Wolff, Conductor, Neal Stulberg, plano Soloist; Sanders; 8:30.

Works of Scriabin and Rachmaninoff; Martha Anna Verbit, Plano, Dunster Library: 5:30.

Works of Dowland, Britten, Villa-Lobos, Mozart, and Serben: Kart Dan Sorensen, Tenor, David Sussman, Gulter; Adams LCR; 7:30.

Works for Chamber Orchestra: The Bridgewater String Quarter with I Solisti di Mather String Orchestra, Mather Dining Hall: 8:00.

Original Compositions performed by Donald Alsmeda. Dunstor Library; 3:00 Monday:

Fromm Music Foundation Presents "When Lilacs last in the Dooryard Bloom'd" by Roger Sessions: the Harvard University Choir among others Sanders; 8:30.