Too good to be forgotten but too minor to champion, the music of Vernon Duke has not received much exposure since the composer's death in 1969. To help remedy the situation, and to celebrate the recent acquisition of the Vernon Duke Collection, the Library of Congress last night presented an evening of Duke's music.

Better known for such popular hits as "I Can't Get Started" and "April in Paris," Vernon Duke also wrote more serious works that he signed with his real name, Vladimir Dukelsky. The Coolidge Auditorium concert gave many in the audience a first hearing of the Russian-born composer's virtually unknown side.

As it turns out, the public has been a good judge. The first half of the program featured a 1949 sonata for violin and piano and a 1956 string quartet, both rather forgettable. Fashionably modern without falling into the daring, the Sonata in D had that dull sameness so familiar to followers of Nadia Boulanger's lesser-known pupils. Only the last movement demanded attention. The String Quartet, played with commitment and vigor by a group called For the Love of Music, revealed an affecting Brahmsian symmetry.

For the rest of the evening, soprano Kay McCracken Duke sang some of her late husband's vocal music, including both art songs and more popular works. Her instrument is small, an embroidered sampler with too many hues. Duke's attempts at more serious songs produced some very derivative music, like the cycle "La Boheme et Mon Coeur," which falls into unintentional Poulenc parody. Perhaps most jarring is the stylistic schizophrenia found in the music, nowhere more evident last night as in "The Night Has a Thousand Eyes," which pitted a traditional pop ballad against pseudo-expressionistic piano writing.

At the close, however, the song came through. Kay McCracken Duke is no Mabel Mercer, but her attention to words and her obvious love for the material worked in favor of the music as she launched into the nostalgic "Autumn in New York" and interpreted more of Duke's best material, including "I Can't Get Started" and the beautiful "Ages Ago." Dale Anthony accompanied with cachet and the venerable Coolidge Auditorum became the nicest piano bar in town.