Anyone who complains that "serious" music written within the last 30 years lacks humor has probably been force-fed a steady diet of Milton Babbitt, Elliott Carter and Karlheinz Stockhausen. Everyone who attended the Inter-American Music Festival last night at the Library of Congress knows better: there's still a bit of Spike Jones sabotage up the sleeves of composers on both continents.

The evening was not all fun and games. Pianist Caio Pagano and percussionist John Boudler variously coaxed and pounded colorful sonorities in a tug-of-war fashion. Oswaldo Lacerda's Suite for Piano, Xylophone, Marimba exploited unusual timbres; Marlos Nobre's Sonancias I for Piano & Percussion was an even more physical exchange, as Pagano's fists and forearms pummeled the keyboard, while Boudler's mallets thundered on the kettledrums.

Boudler provided the first dosage of laughter in "Salute to the Fifties," a percussion parody by Richard Trythall that's a two-fingered eye gouge to eggheads and adolescents. His one-man wrecking crew routine leveled '50s avant-garde mannerisms, exploiting every cliche', as taped fragments of Jerry Lee Lewis' "Whole Lotta Shakin' Going On" intermittently spewed forth from a pair of loudspeakers. Lewis sounded as if he were coming over a car radio 100 miles from nowhere. Boudler, flailing away, eventually took to shouting out the lyrics and shaking his own tailfeather in the process.

If all this wasn't enough to leave one breathless, then the next two pieces certainly did the job. Dressed like T.H.E. Cat, Boudler skulked onto a darkened stage, exaggeratedly mimed playing his battery of percussion in "Cenas Sugestivas," before attacking the instruments and shouting like a madman. Pagano became part of the act in "Blirium C-9" by Gilberto Mendes. True to its title, this was Grade B Delirium, with wacky quotes ranging from Beethoven to "Turkey in the Straw."