Background: Steven Siro Vai (; born June 6, 1960) is an American guitarist, composer, singer, songwriter, and producer. He was voted the "10th Greatest Guitarist" by Guitar World magazine, and has sold over 15 million records. A three-time Grammy Award winner and fifteen-time nominee, Vai started his music career in 1978 at the age of 18 as a transcriptionist for Frank Zappa, and joined his band from 1980 to 1983. He embarked on a solo career in 1983 and has released eight solo albums to date.
Context: In 1978, Vai sent both a notated transcription of Frank Zappa's "The Black Page", and a recording of his college band, Morning Thunder, to Zappa. Impressed by this, Zappa responded by putting Vai on salary as a transcriptionist to transcribe his work, which included pieces from the Joe's Garage and Shut Up 'n Play Yer Guitar albums. After leaving Berklee College of Music and moving to California, Vai auditioned for and became a full-time member of Zappa's band, going on his first tour with Zappa in the fall of 1980. Zappa often referred to Vai as his "little Italian virtuoso", and Vai is frequently listed in the liner notes of Zappa's albums as having performed "stunt" or "impossible" guitar parts.  Vai was a featured artist on the 1993 release Zappa's Universe, and in 2006, Vai appeared as a special guest on Dweezil Zappa's Zappa Plays Zappa tour; both projects won Vai a Grammy Award.  After moving on from Zappa's employ in 1983, Vai bought a house in Sylmar, Los Angeles, where he built his first professional studio. During this period, Vai formed two bands (The Classified and 777) as well as writing and recording a large amount of music that was not originally intended for release. Out of this material, Vai compiled his first studio album Flex-Able. He created his own record label, Akashic Records (later Light Without Heat Records), which he used to take Flex-Able directly to distribution channels. Flex-Able was released in January 1984.  Vai began his rise to public acclaim in 1983 when, shortly before the release of Flex-Able, his composition "The Attitude Song" was published in Guitar Player magazine. The song centered itself on a main guitar riff in the time signature 7/16, played over a rhythm section centered in 4/4. Each following section of the song showcased a number of specialized techniques (such as two-handed tapping, whammy bar acrobatics, sweep picking, alternate picking, multi-part harmonies, and odd phrasing) used in angular and exaggerated ways that were unique to the song at the time. Interest from the public eye grew more so when Vai's song "Blue Powder" (a demonstration for the Carvin X100b amplifier) was published in Guitar Player as well, which showed the virtuoso side of Vai's compositional process. Also in 1986, Vai was cast in the blockbuster film Crossroads as the Devil's guitar player "Jack Butler". In the famous "duel scene" between Vai and Ralph Macchio's characters, Vai wrote and performed all guitar parts with the exception of the slide guitar, which was performed by Ry Cooder.  In between solo work, Vai replaced Yngwie Malmsteen in June 1984 as the lead guitarist of Alcatrazz, with whom he recorded the album Disturbing the Peace. Vai left shortly after the subsequent tour to join David Lee Roth's band.
Question: Did he work with anyone in his studio?

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