"I used to love putting little black dots on music paper," wrote Frank Zappa in his 1989 autobiography The Real Frank Zappa Book. "I'd sit for 16 hours at a time, hunched over in a chair with a little bottle of India ink and draw beams and dots."

For the vast majority of his career in music, Zappa was majorly renowned (or reviled depending on your meddle) for both his superhuman heroics on the electric guitar and his penchant for penning tunes that—had they been written and released in 2018—would surely cause an alarming rate of controversy. Consider songs such as "Jewish Princess," "The Torture Never Stops" or "Bobby Brown (Goes Down)," so rife with salty subject matter one could easily see the moral majority in the United States siding with Tipper Gore and the PMRC back in the mid-80s on offensiveness alone.

However, according to Zappa circa '89, the guitarist's long game was not in sophomoric "porn rock" (as it would be called by his detractors in the U.S. Senate) but rather his work in classical music as a student of such 20th century titans as Igor Stravinsky and Edgar Varese. For Frank, conspiring those naughty little ditties was essentially a means to fund his ability to hire an orchestra to help transform his "little black dots" into symphonic sound—something he had achieved across such classic FZ titles as 1969's Uncle Meat, 1979's Orchestral Favorites and, of course, London Symphony Orchestra Vol. I (1983) and Vol. II (1987).

"Thanks to songs like 'Dinah Moe Humm,' 'Titties & Beer' and 'Don't Eat the Yellow Snow,' I managed to accumulate enough cash to bribe a crew of drones to grind its way through pieces like 'Mo 'n Herb's Vacation,' 'Bob in Dacron' and 'Bogus Pomp'," he wrote, "in performances which come off like high-class 'demos' of what actually resides in the scores."

Zappa spent the entirety of the book's eighth chapter, entitled "All About Music," going into detail of how he largely funded his orchestral work with his own personal money, at a rate by which many rock stars in the '70s and '80s would be spending on cocaine. Save for cigarettes, coffee and wine, Frank led a largely substance-free lifestyle. However, those little black dots proved to be his ultimate vice.

"Definitely playing in what's called a rock n' roll outfit is what paid the bills so he could hire these orchestras," explained Zappa's youngest son Ahmet, who now oversees the Zappa Family Trust along with his sister Diva. "He was a very serious composer and he would experiment with the music he was writing onstage in front of an audience whenever he could. He had many stories about working with orchestras. 200 Motels was an experience. He tried to play the U.K., but got shut down and sued the Queen for the failed Royal Albert Hall experience. It's so interesting how times have changed, and people's sensitivities towards certain subjects have evolved."

When you view it from that perspective, it surely must have been gratifying for Zappa to see the final LP released in his lifetime be a classical album when The Yellow Shark hit record stores 25 years ago today (Nov. 2, 1993). One month later, the composer lost his valiant battle with prostate cancer on Dec. 4, 1993.

The Yellow Shark, the title at least, was based on a piece of artwork hanging on Zappa's wall by Los Angeles artist Mark Beam, who carved a marlin out of a yellow surfboard and had it sent to the artist's house as a present. It caught the eye of Andreas Mölich-Zebhauser, manager of the Frankfurt, Germany-based 18-piece orchestra Ensemble Modern, who happened to be at Zappa's home with the group's conductor, Peter Rundel, talking to Frank about the music the Ensemble commissioned from Frank for a series of concerts in Sept. 1992. Zappa gifted Mölich-Zebhauser the fiberglass fish, which he christened "The Yellow Shark," and chose to base the program around it, introducing Frank to the Ensemble with a mix CD comprised of the group performing selections from the likes of Kurt Weill and Helmut Lachenmann, which greatly impressed the guitarist. He even cited the intonation of the players and how certain aspects of the performance reminded him of Uncle Meat, whose title track helped kick off the album The Yellow Shark, comprised of selections from the fully recorded concerts in Frankfurt that were then edited together by Zappa himself, as he had done on such classic live albums in the past as Roxy & Elsewhere, Shut Up 'n Play Yer Guitar and The Best Band You Never Heard In Your Life.

The initial sessions for Shark came about when the Ensemble flew out to Los Angeles in the summer of 1991 and spent two weeks in rehearsals with Zappa at his Joe's Garage home studio. And despite being sick, the composer would put all 18 members of the orchestra to task, rigorously working with them to perfect his distinctive improvisational techniques, sampling each instrument through the Synclavier that would define so much of his work during those final years. Then, in a technique that’s been expanded upon by such modern visionaries as hip-hop producer Madlib and jazz drummer Makaya McCraven, Zappa would "play" the entire orchestra on the keyboard, only to—with the assistance of copyist/arranger Ali N. Askin and synth specialist Todd Yvega—translated printouts of the Synclavier works’ raw numerical material into written sheet music to give back to the Ensemble. A year later, in July ’92, an even more unwell FZ flew out to Germany to rehearse again with the Ensemble in the midst of a sweltering Deutschland heatwave, working out new variations of Zappa favorites like "Dog Breath," "Be-Bop Tango" and "A Pound for a Brown on the Bus," which according to Zappa in the liner notes to Shark dates back to the late '50s, shortly after he graduated high school.

By the time of the September concerts, the Ensemble Modern were as well-oiled and battle-ready a vessel for Zappa's mad genius as the original Mothers of Invention, dutifully recreating the configurations Zappa painfully crafted in his Utility Muffin Research Kitchen home studio (now owned by Lady Gaga along with the rest of the house to the delight of the Zappa family) in a concert hall setting at the Frankfurt Alte Oper. And while much of the performance was conducted by Rundel, Zappa mustered up the strength to man the wand for three numbers in "Food Gathering in Post-Industrial America, 1992," the insanely frenetic "G-Spot Tornado" (considered one of his most difficult pieces and the one featuring the ballet troupe) and a composition titled "Welcome to the United States." It was an improvised piece based around the I-94W non-immigrant visa waiver/departure form given to citizens leaving the country by the Department of Justice that seems highly foretelling when listening in 2018.

"Well, when I saw the U.S. customs card that must be filled out by persons entering the United States, I couldn't believe that anybody would ask those questions and expect somebody to give honest answers to them," Zappa wrote in the Yellow Shark liner notes. "It just seemed like such a classic piece of governmental stupidity—first, that it exists, and second that people are forced to fill it out. Somewhere, there's whole government machinery that has to deal with filled-out cards. It's so stupid. Since most of the people in the group were German, I know that when they came to the United States, they all had to fill these things out, and probably found it to be especially offensive."

When Zappa stepped onto the stage at the first Frankfurt concert for what would be his last public appearance as an artist, the crowd at the Alte Oper gave him a 20-minute ovation. And when you see the footage in the excellent and touching 2016 documentary Eat That Question: Frank Zappa In His Own Words, you see not the man who gave us such lascivious tunes as "Catholic Girls" and "We're Turning Again," but the maestro—though frail from cancer treatments—beaming with satisfaction in the roar of the audience saluting the three decades he spent hunched over a desk making those little black dots, which, 25 years later, ensure his place in music far greater than any hot guitar lick or distasteful Dadaist lyric ever could.

"I learned that Frank was sick when I was 15," Ahmet Zappa tells Billboard. "So as a family, we all moved to Frankfurt when he had to go out there. And Frank was so sick, so it made it a really emotional time. Getting that performance done was so emotional for the entire family, because we knew that was the last big project he was ever going to do. It was so important that it happened, and it brought Frank so much joy."