The closing theme of Sesame Street, the whistling in Old Spice commercials, jam sessions with Charlie Parker and Miles Davis, and the guitar that convinced a young John Lennon to play a Rickenbacker all trace back to one man: Jean-Baptiste Frederic Isidore Toots Thielemans. This episode follows the Brussels cafe owner’s son who played a cardboard accordion at three, entered college as a mathematics major, and taught himself guitar by ear from Django Reinhardt records during the German occupation of Belgium. When American bebop records flooded Europe after 1945, he abandoned his degree entirely.

The hosts recount how a Benny Goodman agent heard him in a New York club in 1948, how the Goodman European tour turned out to be his first paid gig, and how British Musicians Union rules at the London Palladium barred his guitar but not the harmonica nobody considered a real instrument. They explain the chromatic harmonica’s slide button and why the jazz world assumed it could not keep up with bebop, his years in the George Shearing Quintet, the 1960 Hamburg gig where Lennon watched him play, and the 1962 jazz waltz Bluesette with its guitar-and-whistle unison that drew more than a hundred cover versions. Later chapters cover Midnight Cowboy, The Sugarland Express, sessions with Billy Joel and Paul Simon, work with Quincy Jones and Jaco Pastorius, his elevation to baron by King Albert II in 2001 with the motto be yourself, no more, no less, and his death in 2016 at 94.

• Reverse-engineering Django Reinhardt by ear as a form of pattern recognition
• The union loophole that accidentally launched the harmonica as a jazz instrument
• How the Shearing Quintet’s Hamburg show shaped the Beatles’ guitar choice
• The neural coordination behind whistling and playing Bluesette in unison
• A metro station, an asteroid named 130079 Toots, and a message from President Obama at his funeral