Answer by taking a quote from the following article:

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.

After the breakup of the Butterfield Blues Band and no longer under contract with Elektra, Butterfield retreated to Woodstock, New York, where he eventually formed his next band, Paul Butterfield's Better Days, with drummer Chris Parker, guitarist Amos Garrett, singer Geoff Muldaur, pianist Ronnie Barron and bassist Billy Rich. In 1972-1973, the group recorded the albums Paul Butterfield's Better Days and It All Comes Back, released by Albert Grossman's Bearsville Records. The albums reflected the influence of the participants and explored more roots- and folk-based styles. Although without an easily defined commercial style, both reached the album chart. The band did not last to record a third studio album, but its album Live at Winterland Ballroom, recorded in 1973, was released in 1999.  Butterfield next pursued a solo career and appeared as a sideman in several different musical settings. In 1975, he again joined Muddy Waters to record Waters's last album for Chess Records, The Muddy Waters Woodstock Album. The album was recorded at Levon Helm's Woodstock studio with Garth Hudson and members of Waters's touring band. In 1976, Butterfield performed at the Band's final concert, "The Last Waltz", accompanying the Band on the song "Mystery Train" and backing Muddy Waters on "Mannish Boy". Butterfield kept up his association with former members of the Band, touring and recording with Levon Helm and the RCO All Stars in 1977 and touring with Rick Danko in 1979. A 1984 live performance with Danko and Richard Manuel was recorded and released as Live at the Lonestar in 2011.  As a solo act with backing musicians, Butterfield continued to tour and recorded the misguided and overproduced Put It in Your Ear in 1976 and North South in 1981, with strings, synthesizers, and pale funk arrangements. In 1986, he released his final studio album, The Legendary Paul Butterfield Rides Again, which again was a poor attempt at a comeback with an updated rock sound. On April 15, 1987, he participated in the concert "B.B. King & Friends", with Eric Clapton, Etta James, Albert King, Stevie Ray Vaughan, and others.

what kind of other musical setting he was in?
In 1975, he again joined Muddy Waters to record Waters's last album