Paul Vaughn Butterfield (December 17, 1942 - May 4, 1987) was an American blues harmonica player and singer. After early training as a classical flautist, he developed an interest in blues harmonica. He explored the blues scene in his native Chicago, where he met Muddy Waters and other blues greats, who provided encouragement and opportunities for him to join in jam sessions. He soon began performing with fellow blues enthusiasts Nick Gravenites and Elvin Bishop.

Butterfield was born in Chicago and raised in the city's Hyde Park neighborhood. The son of a lawyer and a painter, he attended the University of Chicago Laboratory Schools, a private school associated with the University of Chicago. Exposed to music at an early age, he studied classical flute with Walfrid Kujala, of the Chicago Symphony Orchestra. Butterfield was also athletic and was offered a track scholarship to Brown University. However, a knee injury and a growing interest in blues music sent him in a different direction. He met guitarist and singer songwriter Nick Gravenites, who shared an interest in authentic blues music. By the late 1950s, they were visiting blues clubs in Chicago, where musicians such as Muddy Waters, Howlin' Wolf, Little Walter, and Otis Rush, encouraged them and occasionally let them sit in on jam sessions. The pair were soon performing as Nick and Paul in college-area coffee houses.  In the early 1960s, Butterfield met aspiring blues guitarist Elvin Bishop. Bishop recalled:  He [Butterfield] was playing more guitar than harp when I first met him. But in about six months he became serious about the harp, and he seemed to get about as good as he got in that six months. He was just a natural genius. This was in 1960 or 1961. By this time Butter had been hanging out in the ghetto for a couple of years, and he was part of the scene and getting accepted.  Eventually, Butterfield, on vocals and harmoica, and Bishop, accompanying him on guitar, were offered a regular gig at Big John's, a folk club in the Old Town district on Chicago's North Side. With this booking, they persuaded bassist Jerome Arnold and drummer Sam Lay (both from Howlin' Wolf's touring band) to form a group with them in 1963. Their engagement at the club was highly successful and brought the group to the attention of record producer Paul A. Rothchild. Answer this question using a quote from the following article:

Did he meet any other musicians during the beginning of his career ?