Schubert's song, "The Shepherd on the Rock" ("Der Hirt auf dem Felsen"), is one of the glories of his last years -- a feast of pure melody, hauntingly evoked landscape and feeling, and intricate structure (almost a vestpocket concerto) that proves a piece of music need not be long or pondercus to be a masterpiece.

We do not hear it as often as it deserves, because Schubert wrote in a clarinet as the equal and indispensable partner of the soprano and piano, and it seems extravagant to bring a clarinetist into an otherwise vocal recital for such a brief appearance -- even in a brief masterpiece.

Last night at the Library of Congress, soprano Phyllis Bryn-Julson, clarinetist Sidney Forrest and pianist Cary Lewis did this music complaete justice. One could hardly ask for more, but they provided more -- including an interesting solution to the problem of how to build a whole program for soprano, clarinet and piano.

The other vocal works (with clarinet) by Ludwig Spohr and Dominick Argento suffered in comparison, but the instrumental works were better. Weber's Grand Duo Concertante is brilliant and was treated as such; Burnet Tuthill's Fantasy Sonata is pleasantly, melodiously old-fashioned, and Witold Lutoslawski's Dance Preludes are a tour de force -- jazzy, moody, mocking and technically dazzling. They received the second-best performance of the evening.