Monk Montgomery: Jazz bass player: Monk himself did not take up the double bass until he was 30, after hearing one of Wes' groups perform.
Hard to say that he knew nothing about music beforehand, but certainly not too much and no formal training - just a lot of talent and a lot of ambition.
I read in an interview with him from back in the 80's. He said that when he decided to learn how to play bass, he bought a cheap upright bass and played all night in the basement while he was working his day job, just working on scales and playing cleanly. He did that for quite a while, until he felt ready to go out and try to play in a band:
Photograph of William 'Monk' Montgomery, electric bass player, on tour with Lionel Hampton and his Orchestra, Sweden, 1953. Seen here with a Fender Precision Bass. Original source: Estrad magazine, October 1953:
That is a very early Fender PBass he's playing - looks like the first version they produced - 1951. (Note his 'homebrew' thumb technique, which was reportedly how Leo Fender believed his bass should be played, placing a finger rest on the upper right side of the bass in the original design, shown clearly below.)
The bass that changed the world - 1951 Fender Precision Bass - Original, first year of commercial production:
William Howard "Monk" Montgomery (October 10, 1921 – May 20, 1982) was an American jazz bassist. He was a pioneer of the electric bass guitar and possibly the first to record on it when he recorded with Art Farmer in 1953. He was the brother of jazz guitarist Wes Montgomery and vibraphonist Buddy Montgomery.
Born in Indianapolis, Indiana, into a musical family, Monk had three brothers and a sister. His older brother Thomas played drums, and died at 16. Monk gave his younger brother Wes (born 1923) a tenor guitar when Wes was 11 or 12. Wes took up the electric guitar at age 19 and went on to major success. The youngest brother, Buddy (born 1930) played piano and later took up the vibraphone. Their younger sister, Ervena (Lena), also played piano.
Monk himself did not take up the double bass until he was 30, after hearing one of Wes' groups perform.
The three brothers released a number of albums together as the Montgomery Brothers also playing together on some albums credited to Wes. Also Buddy and Monk recorded many albums together in their group The Mastersounds.
He is perhaps the first electric bassist of significance to jazz, taking up the Fender Precision Bass in 1952 or '53 after replacing Roy Johnson in the Lionel Hampton Orchestra. He said his biggest influences as a bassist were Jimmy Blanton, Ray Brown, and Charles Mingus.2 Monk played electric bass with his thumb (brother Wes, played electric guitar with his thumb, also) and adapted his jazz playing from double bass to electric. In the 1960s he took up Fender Jazz Bass, playing with a felt pick.
His professional career did not start until he was 30, and after his younger brother Wes. Monk worked in a foundry and played gigs on upright bass at night in Indianapolis. Wes worked for vibraphonist Lionel Hampton from 1948–1950, Monk then worked for Hampton around 1952–1953, with Hampton insisting he play the Fender bass, and not an upright.
Monk's recordings with The Art Farmer Septet on 2 July 1953 are possibly the earliest recordings of the electric bass, and display his facility with walking bass lines, bebop melodies, and Latin-style ostinato. Chuck Rainey said that Monk was the first electric bassist to record, in any genre.
Guys in other kinds of music may have beat me to the studio, though I'm not aware of any...As far as I know, I was the first in jazz to record electric bass.
— Monk Mongomery, Guitar Player, September 1977, reprinted in The Guitar Player Book, 1979