Jean-Baptiste Frédéric Isidor, Baron Thielemans (Brussels, Belgium, April 29, 1922 - August 22, 2016), known as Toots Thielemans, was a Belgian jazz musician. He was known for his harmonica playing, as well as his guitar and whistling skills. A jazz standard by Toots Thielemans is "Bluesette," where he used whistling and guitar in unison. He worked both as a bandleader and as a sideman, including many projects with composer/arranger Quincy Jones.