Superb violinist Ian Swensen may be more self-effacing than his better-known contemporaries, but that's all to the advantage of San Francisco Conservatory students, who will get to play with him in a rare performance of the French Romantic Ernst Chausson's Concerto for Violin, Piano, and String Quartet. Swenson also is joined by fellow faculty members Corey Jameson and Elizabeth Reed for an 18th-century sonata by Leclair, and, if that's not enough, will throw in music by 20th-century American composer Lukas Foss for good measure.