"The interesting part about that period is that the composers tailored the songs to the stars," says mezzo-soprano Joan Morris. "Mae West knew exactly the kind of materials she wanted." Pianist William Bolcom adds, "And if a singer had a small range, they gave the song a small range." Bolcom and Morris, who since 1972 have been performing American popular songs from the late 19th century through the 1930s, will offer a two-part program Wednesday in Baird Auditorium. Sponsored by the Smithsonian Resident Associates, the evening will begin with a centennial salute to Jerome Kern and conclude with a look at music written for the movies.

The duo will concentrate on "quintessential movie songs," says Bolcom, citing tunes that Kern wrote for "Swing Time" and George Gershwin for "Top Hat," both of which are Fred Astaire-Ginger Rogers vehicles. "They had to be conceived visually," Morris points out, "and you had to see the pattern of what the singer was going to do -- did Astaire need a break there to put a few dance steps in?"

As for social commentary in the lyrics, "it was a rarity," says Bolcom. "You had to get it past the studio moguls, who wanted something that would bring money in the box office, not something to remind people how terrible things were."