At night, Kleinow would frequently sit in with Bakersfield Sound-oriented combos and early country-rock aggregations playing the pedal steel guitar. Through this scene he became acquainted with Chris Hillman and Gram Parsons of The Byrds, helping the group to replicate their newly country-oriented sound onstage with banjoist Doug Dillard.
After leaving the Byrds, in 1968, Parsons and Hillman invited Kleinow to join their new band, the Flying Burrito Brothers. Subsequently, Kleinow left behind his career in visual effects and spent the next thirteen years as a professional musician.
One of the first pedal steel players to work in a rock context, Kleinow incorporated liberal use of electronic innovations like the fuzzbox and backwards recording techniques. As such, his style of playing was immediately influential upon second-generation players such as Jerry Garcia, Buddy Cage of the New Riders of the Purple Sage and sessionman Al Perkins.
Respected as the "Hendrix of the steel guitar," Kleinow was rarely short of session work. Finding session work to be more lucrative, he left the Flying Burrito Brothers in 1971 and played for an eclectic range of artists, including Joe Cocker (Joe Cocker!, 1969), Delaney, Bonnie and Friends (To Bonnie from Delaney, 1970) and Little Feat (many albums including Sailin' Shoes, 1972). In 1972 Sneaky teamed up with Laramy Smith in the group ARIZONA. Other members included Steve Ewards (Spirit), David Atwood (America) and Andrew Way (Spencer Davis Group).
He also added steel guitar to records by Frank Zappa (Waka/Jawaka, 1972), the Bee Gees (Life in a Tin Can, 1973), John Lennon (Mind Games, 1973), Linda Ronstadt (Heart Like A Wheel, 1974), and Fleetwood Mac (Heroes Are Hard to Find, 1974).
In 1974 Kleinow was part of a new band, Cold Steel, and then a reconstituted Flying Burrito Brothers. His first solo album, Sneaky Pete, was released in 1978 and The Legend and the Legacy followed in 1994.
He returned to special effects and created the dinosaurs for the comic film Caveman (1981), starring Ringo Starr and Barbara Bach. Throughout the 1980s and 1990s, Kleinow created special effects for movies such as The Empire Strikes Back, Gremlins, The Right Stuff, The Terminator, and Terminator 2, while continuing to work sporadically as a professional musician.
In 2000, Kleinow formed a group called Burrito Deluxe (also the name of a 1970 Flying Burrito Brothers album) with Garth Hudson, former organist of The Band, Carlton Moody of the Moody Brothers on lead vocals and guitars, bassist Jeff "Stick" Davis of Amazing Rhythm Aces and drummer Rick Lonow. The group recorded three albums, Georgia Peach, The Whole Enchilada and 2007's Disciples Of The Truth, which feature his last studio recordings. Kleinow's last performance was at a 2005 Gram Parsons tribute concert in Waycross, Georgia, the home town of Gram Parsons.
Kleinow was survived by his wife, three sons and two daughters.