To get technical, 1971 when creators Forrest White, Leo Fender (above & below), and Tom Walker, then unhappy employees of the CBS owned Fender left to create their own, first Tri-Sonic, then Musitek, Inc., and finally onto MusicMan Inc in 1974. At this time, Leo Fender had more than just this project, he was also running a consulting firm called CLF (Clarence Leo Fender) out of Fullerton, California.
It appears that their first production was the Sixty Five, which was designed in part by Leo Fender. By 1976 the StingRay (below) appeared with Sterling Ball as the beta tester for the bass. From here it seems things went crazy with more artists signing on, and creative thinkers like Dudley Gimpel to expand the Music Man designs.
Their instruments appear to all be handmade (although I haven’t read in writing this fact) in a CLF factory, while the amplifiers were made in the Music Man factories, but by 1980 tension grew between the CLF and Music Man entities, thus enter G&L Inc circa. May 1980.
I say handmade because all of the photographs of the building of the instruments are shown with hands only, no machines.
The instruments are known for their cutting edge precision and electronics. They are some of the first guitars to have active pickups, and other ground breaking technologies.
Some bassists you may know that ride on a Music Man are Rex Brown (Pantera), Paul D’Amour and Justin Chancellor of Tool, Flea (Red hot Chili Peppers), Gord Sinclair (The Tragically Hip), Cliff Williams (AC/DC). I know, an incredible lineup.
Some of the guitarists that sport them are Albert Lee, Steve Lukather (Toto), Steve Moorse (Deep Purple, Kansas and Dixie Dregs), Ronnie Wood and Keith Richards of The Rolling Stones, and John Fogerty (Creedence Clearwater Revival).
Who uses their amps is an stunning lineup from Chet Atkins, Eric Clapton, Joe Strummer, Robbie Robertson, Johnny Winter, Jeff Beck, Joan Jett, and Mark Knopfler.
Clearly these guys make serious instruments for the professional.