Guitarist Frank Zappa was best known for his intricate brand of rock music, coupled with a sardonic social commentary. Not as well known is the classical side of his composing.

This month, the Philadelphia-based new music ensemble Orchestra 2001 will explore that territory with two concerts. On Sunday, April 22, they’ll pair some of Zappa’s classical works with those of the 20th century composers who most influenced him.

“Number one is Edgard Varèse,” Jayce Ogren, Artistic Director of Orchestra 2001, explained to WHYY’s Dave Heller how Zappa first heard the French-American composer while in his teens. “Varese became Zappa’s first hero, but it really was a jumping off point for him to start to listen to the other greatest composers of the time, like Igor Stravinsky and Anton Webern, and later on, Pierre Boulez.”

In planning the program, Ogren wanted to show some of the musical ideas that inspired Zappa, side by side with Zappa’s resulting work. “For example, there is an asymmetrical rhythmic drive to some of Zappa’s pieces, such as ‘The Dog Breath Variations,’” he said. “It’s a groove that has a hitch at the end, like a little waltz rhythm at the end of the bar. Zappa was inspired by Stravinsky, who was one of the first composers to make this asymmetric rhythmic drive a regular part of the musical language.”

The second concert, on April 28th will offer the Philadelphia premiere of one of Zappa’s last classical compositions, “The Yellow Shark,” which he described as the best representation of his orchestral works. Ogren says it demonstrates how Zappa went beyond his influences in his compositions.

“What I find so remarkable about Frank Zappa is that, without any training in Western classical music, besides a year of composition lessons, he was able to absorb the influences of the greatest composers of the 20th century,” says Ogren. “Then he put them through the sausage machine of his own emotions and world view and create something entirely new.”

Orchestra 2001 will present “Zappa’s Radical Classical Roots” on Sunday, April 22 at World Café Live, and “Celebrating Frank Zappa’s The Yellow Shark” on Saturday, April 28 at the Fillmore.