Barney Kessel. Some younger musicians and fans understandably might not know Kessel (pictured), who died of a brain tumor in 2004 and previously had been inactive since suffering a stroke back in 1992, but for a long stretch of the 20th century, he was one of the busiest and most respected jazz guitarists in the world.
Born in 1923 in Muskogee, OK - yes, the very same town later immortalized in song by Merle Haggard - Kessel began his career as a teenager influenced by Charlie Christian, working with local bands and later, interesting, doing a brief stint with a unit led by Chico Marx of the Marx Brothers. After landing in NYC, in the 1940s and 50s he performed and recorded with jazz greats including Lester Young, Charlie Parker, Billie Holiday, Oscar Peterson, Sonny Rollins, and many more, and ultimately went on to make more than 30 albums under his own name as well.
His trio recordings with Ray Brown on bass and Shelly Manne on drums offer some good examples of Kessel's signature "chord-melody" style, which, as the name implies, involves improvising by playing chords with (usually) top notes that simultaneously express melodic ideas.
During the 1950s, 60s and 70s, Kessel also was one of the most in-demand session guitarists in America, playing thousands of recording sessions for movies and TV and with the musicians now known collectively as "The Wrecking Crew," who made hundreds of famous pop records with Phil Spector, The Beach Boys, The Monkees, and many others. He was well known enough during this period that Gibson made a Barney Kessel signature model from 1961 to 1973.
Later in his career, Kessel presented guitar workshops and master classes in various locations around the world, and worked in a trio format with Herb Ellis and Charlie Byrd as "The Great Guitars".
The embedded video below, recorded in the 1980s, features Kessel teaching improvisation concepts in the chord-melody style, including "how to play what you hear, fills, turnarounds, the building blocks of improvisation," and the blues.