Dweezil Zappa has set out on what is, for him, the mother of all musical missions. He is, of course, the son of Frank Zappa -- the composer, lyricist, band leader and guitarist who, as they also said about Duke Ellington, was "beyond category." Dweezil has taken a band of young, virtuoso musicians on the road to spur interest in the work of his father -- especially among 20- and 30-somethings.

The Zappa Plays Zappa tour, led by Dweezil on guitar performs its versions of pieces by the utterly iconoclastic Frank, who died of prostate cancer in 1993 at the age of 52.

"He was a composer who used a rock band as his orchestra for the majority of his career," Dweezil says on the phone from a hotel room in Poughkeepsie, N.Y. "A very skilled composer and arranger, and much of what he did was overlooked and misunderstood.

"Part of the thing for me that is most difficult and yet so satisfying is that I'm able to re-educate people and give them a different perspective of what to look for in his music. Because the average person who has only had casual contact with the music -- songs like "Valley Girl," "Don't Eat the Yellow Snow," "Titties and Beer" -- that's sort of unfair to Frank's whole body of work, over 80 albums. That's not representative of what he's capable of. So people may dismiss his music or think of him as like Weird Al Yankovic if that's the only stuff they've ever heard."

Dweezil, who will turn 40 on Sept. 5, gained some recognition in the late '80s with his Eddie Van Halen-style guitar playing and humorous songs like "My Guitar Wants to Kill Your Mama." He was an MTV-VJ, and he landed roles in the movies "The Running Man" and "Pretty in Pink." In the mid-'90s, he voiced a character in the animated sitcom "Duckman." He also made two CDs with his brother Ahmet in the band Z. But the '90s, he explains, were generally not kind to metalesque guitar-god pyrotechnics.

"When I started playing guitar seriously, hard rock was the most popular music in the world. Van Halen was the biggest band in the world back in, say, 1982. So the biggest influences I had at that time were Randy Rhoads [who played with Ozzy Osbourne and Quiet Riot], Eddie Van Halen, Jimmy Page, Angus Young. The solos were mini-compositions of their own. They were definitely worked out, and they were things that people spent time to develop specific techniques to play.

"And over a long period of time, [that style of] guitar playing became somewhat of a joke and sort of disappeared. Because of all the technical requirements and gymnastics. Some people took it to an extreme level where it wasn't necessarily musical anymore, it was just a technical exercise."

Dweezil devoted more than two years to reinventing his guitar playing and studying every one of his father's recordings before he took Zappa Plays Zappa on the road in 2006.

"The whole process was the equivalent of having to get a lobotomy and relearning how to walk. Because the way that Frank played was very different from a normal guitar player. He started off his musical training as a drummer and percussionist. He had gone to a library and taught himself how to become a composer by reading books. He didn't go to school and have formal training. And I think that made a big difference in terms of how his music sounds, and the things that he tended to gravitate towards and combine. Because in many cases some people would say, 'Well those things don't go together. Why would you do that?' And that's precisely why he would do it."

Zappa's music veered from rock to jazz to doo-wop to avant-garde classical -- sometimes within a single song. With his band The Mothers of Invention, he caught the public's ear in the '60s with LPs including "Freak Out," "Absolutely Free" and "We're Only in It for the Money." He went solo with the mostly instrumental "Hot Rats." He continued on to embrace modern classical techniques such as musique concrete (dissonant collages of electroacousitc music) and sprechstimme (spoken melody). The renowned modernist composer/conductor Pierre Boulez commissioned and recorded Zappa's compositions. Zappa also released a series of instrumental albums entitled "Shut Up 'n' Play Yer Guitar."

"In terms of his guitar playing," Dweezil says, "he really thought of solos as spontaneous compositions and moving shapes and creating 'air sculptures,' as he described it. Most guitar players become comfortable with patterns and a few licks that they throw around. And it's something they do over and over and it may sound very good, but in the context of Frank's music, it's unnecessary to think or behave that way," he says with a laugh.

Dweezil also wanted to perform some of the marimba and keyboard parts on the original recordings on guitar. It's music that "does not sit well" on the guitar, he says, including the outro/interlude of "St. Alfonzo's Pancake Breakfast," the interludes in "Inca Roads" and the tune "G-Spot Tornado." This required his learning "sweep" picking, a technique largely developed by Frank Gambale, guitarist with the jazz and fusion keyboardist Chick Corea.

"I don't think too many people would go through the process of transformation unless they were really motivated by a love for the music, which is the only thing that gave me the strength to hold the course. Because some of the stuff that I had to learn and practice, it was 6, 7 or 8 hours a day of playing a phrase that would go by, if you were playing it in tempo, in under a second."

But Dweezil had already learned that such obsessive attention to detail could pay off -- through a hobby he had picked up a decade before.

"During that period in the early '90s, there was so little interest in the kind of skills that I had already spent time to learn, all those rock things, there was no place to put those skills to work. So I actually really wasn't playing much guitar during that period. I was doing some other stuff, including playing some golf," he says and laughs again. "I got to be a two handicap and could shoot rounds under par. And in the process of learning how to be better at golf, there was a parallel in terms of a practice regimen."

Frank Zappa was inducted into the Rock Hall of Fame in 1995, and he received the Grammy Lifetime Achievement Award in 1997. One of the factors in his impact that cannot be replicated is the era in which he worked. The '60s were a time of culture wars that make today's Limbaugh vs. Obama battles seem polite by comparison.

Frank, a singular-looking fellow with his long hair, hawklike nose, mustache and soul patch, was a sharp-tongued satirist of both the hippie counterculture (he was fervently anti-drug) and the establishment. He once spent 10 days in jail as the victim of a sting operation in which an undercover cop offered to pay him to record an audio tape of simulated sex noises for a stag party. The audio was judged "obscene."

When he was in his very early 20s "the adult society was still very McCarthy Era, so it was kind of like 'You better fit into society or we're going to make life very difficult for you.'"

That is why, Dweezil says, his father "had such a steely resolve for the Constitution and why he had such a political voice in his music. He had songs like, 'Dicky's Such an A--hole,' about the president of the United States, at the time when he was in office, or on his way out. And you know, Frank had all the facts to support any of his opinions. He wasn't just borrowing somebody else's opinion and then making a sound bite out of it. He was very astute, and he was pretty unflappable. He was never at a loss for words."

Or for music.