IIRC, he once said he was influenced be Varese.
"Usual source" to the rescue again, I'd say more than just "influenced":
"R&B singles were early purchases for Zappa, starting a large collection he kept for the rest of his life.
[9]:36 He was interested in sounds for their own sake, particularly the sounds of drums and other percussion instruments. By age 12, he had obtained a snare drum and began learning the basics of orchestral percussion.
[1]:29
Zappa's deep interest in modern classical music began[13] when he read a LOOK magazine article about the Sam Goody record store chain that lauded its ability to sell an LP as obscure as The Complete Works of Edgard Varèse, Volume One.[1]:30–33 The article described Varèse's percussion composition Ionisation, produced by EMS Recordings, as "a weird jumble of drums and other unpleasant sounds". Zappa decided to seek out Varèse's music. After searching for over a year, Zappa found a copy (he noticed the LP because of the "mad scientist" looking photo of Varèse on the cover). Not having enough money with him, he persuaded the salesman to sell him the record at a discount.[1]:30–33 Thus began his lifelong passion for Varèse's music and that of other modern classical composers. He also liked the Italian classical music listened to by his grandparents, especially
Puccini's opera arias.
By 1956, the Zappa family had moved to
Lancaster, a small
aerospace and farming town in the
Antelope Valley of the
Mojave Desert close to
Edwards Air Force Base; he would later refer to Sun Village (a town close to Lancaster) in the 1973 track "Village of the Sun".
[14] Zappa's mother encouraged him in his musical interests. Although she disliked Varèse's music, she was indulgent enough to give her son a long-distance call to the composer as a 15th birthday present.[1]:30–33 Unfortunately, Varèse was in Europe at the time, so Zappa spoke to the composer's wife and she suggested he call back later. In a letter, Varèse thanked him for his interest, and told him about a composition he was working on called "Déserts". Living in the desert town of Lancaster, Zappa found this very exciting. Varèse invited him to visit if he ever came to New York. The meeting never took place (Varèse died in 1965), but Zappa framed the letter and kept it on display for the rest of his life.[13][nb 3] "
Perhaps surprisingly to some, I'd actually already been turned on to music concrete by the live '67 version of "the Pusher" found on side B of
Early Steppenwolf, also claimed by John Kay to be influenced by Varese, in the liner notes. Loved the way it gradually segued into something "recognizable".
Best buddy in high school was already a confirmed Zappa fan, turned me on to him, although I was never truly a fan of the "comedy music", preferred the instrumental stuff, especially the jazz-influenced pieces. First Zappa album I ever bought was
Waka Jawaka, for "Big Swifty", but first tunes of his I
really liked were '"My Guitar Wants to Kill Your Mama" and "Trouble Every Day".
(Note the homage to the T-bones' "No Matter What"
)
Zappa also claimed Stravinsky as another source of inspiration, particularly "the Firebird". The acoustic solo in the title tune of '79's
Sleep Dirt is another all-time favorite, I believe it was the first and possibly only(?) acoustic Zappa on record:
Enjoy.
