The keyboardist grew up in Connecticut with the name of Tommy Mariano, spending childhood years in Naugatuck, then moving on to the thrilling territory of West Hartford. It was there that he graduated from the Hartt School of Music in 1972, remembered by at least one colleague as one of "the most interesting individuals on the planet." Apparently the stylistic interests that would satisfy Zappa's fussy ear were already falling into place in the West Hartford days. Still Mariano, the man who would be Mars was quite likely to use his left hand to pound in a modal spike right out of McCoy Tyner's toy railroad kit. His next move, literally on the other hand, would reflect a cunning understanding of modern classical masters such as Béla Bartók and the somewhat neglected Paul Hindemith.

Those observing, including one of his former next-door neighbors, would have noticed a transition in the keyboards themselves, a familiar progression that in itself comments on some of the musical trends an instrumentalist such as Mars would have riffed through beginning in the early '80s. As a student he had begun on a normal piano, plus a touch of upright bass. Then came the cumbersome Hammond organ with twirling Leslie speaker, next the crinkle and lesser physical load of a Fender Rhodes electric piano, then a sprinkling of analog synthesizer settings and patches. Meanwhile he still had time to be an important influence on that kid next door, according to an Internet report: "...although he was older, he was very friendly to me growing up. He showed me how to skateboard, ride a bike, smoke my first cigarette, choose bellbottoms, and scat...." The last reference is to scat singing, not ringing doorbells and running. Associated mostly with jazz, the art of scat is loosely defined, requiring a proper swing feel, like anything associated with this genre, combined with more than a touch of lunacy in the form of nonsense syllables à la "scoobdoobdeebdoob."

It was a talent that would come in handy once Mars was installed in the Zappa band; it was in fact the single talent that allowed him to triumph at his original audition with Zappa. This chance did not come immediately after Mars graduated from music school. In between came all manner of music jobs: choirmaster, church organist, movie accompanist, cheesy hotel lounge keyboardist. He dabbled with his own band after college, calling the combo Mars. Eventually he headed west to California, attempting to establish a solo act. His desperation to find music jobs led to what he has described in Keyboard magazine as a "revolving organ bar in Kodiak, Alaska, with Japanese and Russian fishermen kicking me in the back if I couldn't play an ethnic folk song to their drunken satisfaction."

Speaking of ethnic songs, there is the Romanian one about the man who had seen the bear, which in this case should be the Mann who had seen the bear, as in Ed Mann, a percussionist friend from back home. Mann was doing well on the West Coast, playing percussion with Zappa, among other things. In Romania, the bear symbolizes a figure of great importance and influence and Zappa was certainly that to most young musicians by the '70s. Mann helped arrange an audition for Mars when Zappa was on the prowl for additional keyboards, a stringent test that Mars was sure he was flopping until it came time for the orals, as in a vocal portion. Mars can be sighted in the original lineup of Zappa albums beginning with Sheik Yerbouti in 1979. His presence continues for another decade and onward, despite the fact that he was no longer actually in a Zappa band. An initial wave of CD box collections of previously unissued material, much of it tracked live, began appearing almost on cue with Zappa disbanding his touring operations.

In 1988 Mars performed and recorded with Stuart Hamm and in the early '90s was involved with both Vai and Mann from the Zappa camp. On Vai's Flex-Able album, Mars performs on violin. He recorded and toured with the Mona Lisa Overdrive band in 1994 and was reportedly working during that period on a solo album to be issued as part of a recording venture engineer Bob Stone was involved in. Activity involving the music of Zappa continued through the close of the 20th century. Mars toured as part of the Band from Utopia (aka Banned from Utopia), an alumni ensemble that has involved players such as Arthur Barrow, Ralph Humphrey, Ike Willis, Ray White, and various members of the Fowler clan; pick a first name, attach it to Fowler and there will be a dude standing there with some instrument ready to sight-read a Zappa chart. Mars has also collaborated with players from even earlier Zappa periods, such as the maestro's very first and arguably greatest band, the Mothers of Invention. At an ad-hoc 2000 performance for a lively Sicilian festival crowd, Mars and drummer Jimmy Carl Black displayed their flair at performing many of their former boss' extended-form compositions, a performance that was subsequently released by the Indian of the group's Inkanish imprint.

Later in the decade Mars would reside in Venice, CA, and be active as a keyboard instructor, while playing and recording now and then with Band from Utopia members and others, at one point rechristened as the Mar Vista Philharmonic and consisting of Mars along with the aforementioned Fowlers (Bruce on trombone and Walt on trumpet and flügelhorn) and Arthur Barrow (bass) along with Kurt McGettrick (bass clarinet, baritone sax), Larry Klimas (tenor and soprano sax), and Vinnie Colaiuta (drums). Assembling at Barrow's Lotek Studio in Los Angeles during August 2002, this aggregation recorded four improvisations released as No Forest Fire on the independent Zonic Entertainment imprint in 2009. Mars could also be heard on the 2007 Zonic release Strange News from Mars, a jazz fusion outing led by Norwegian guitarist Jon Larsen and also featuring Barrow, Bruce Fowler, and Jimmy Carl Black, among others.