Recordings: Elvira, Meet Wolfgang

RECORDINGS Elvira, Meet Wolfgang It is impossible to predict where a composer's next record hit will come from, even if the composer is Mozart. A case in point is Deutsche Grammophon's 1965 release of Mozart's Piano Concerto No. 21, played by Hungarian-born Pianist Geza Anda. In three years it had sold a mere 2,000 copies in the U.S. Then a passage from the recording turned up as a recurrent, haunting theme on the sound track of the Swedish film Elvira Madigan, which opened in New York City last October. Deutsche Grammophon slapped a promotional sticker on the album ("Contains theme from Elvira Madigan").

Suddenly the pianissimo sales grew into what for a classical record amounts to a forte. Although until recently the film was playing-in only four U.S. cities, the album has now sold 15,000 copies. This week Mozart's "new" hit climbed to No. 21 on Billboard's chart of bestselling classical records. And the surge is spreading to other versions: RCA's five-year-old issue, played by Artur Rubinstein, is selling four times faster since Elvira arrived.