Jean-Baptiste Frederic Isidor, Baron Thielemans (29 April 1922 - 22 August 2016), known professionally as Toots Thielemans, was a Belgian-American jazz musician. He was known for his harmonica playing, as well as his guitar, whistling skills, and composing. According to jazz historian Ted Gioia, his most important contribution was in "championing the humble harmonica", which Thielemans made into a "legitimate voice in jazz". He eventually became the "preeminent" jazz harmonica player.

During the early 1980s Thielemans was a guest a number of times on Late Night with David Letterman. He has performed with the bassist Jaco Pastorius, and in 1983 he contributed to Billy Joel's album An Innocent Man, in the song, "Leave A Tender Moment Alone." (The two later collaborated on this selection in concert, and this was recorded on video.) A year later, he appeared on the Julian Lennon song "Too Late for Goodbyes" from the album Valotte.  In 1984, he recorded with Billy Eckstine on the singer's final album (I Am a Singer), featuring ballads and standards arranged and conducted by Angelo DiPippo. In the 1990s, Thielemans embarked on theme projects that included world music. In 1998 he released a French-flavoured album titled Chez Toots featuring guest singer Johnny Mathis.  During those years, he often recorded songs as personal tributes to those who were influential during his career. On Chez Toots, for example, he included "Dance For Victor," which he dedicated to his sometimes keyboard accompanist, Victor Feldman. Similarly, he recorded "Waltz for Sonny" as a tribute to saxophonist Sonny Rollins. In June 1998, at Germany's Jazzbaltica, he paid tribute to Frank Sinatra who died a month earlier. And during the first Caspian Jazz and Blues Festival in Azerbaijan in 2002, he performed his recorded version of "Imagine," his tribute to its writer, John Lennon.  Thielmans was well liked for his modesty and kind demeanor in his native Belgium, and was known for describing himself as a Brussels "ket," which means "street kid" in old Brussels slang.

What was the hit they released together?
Leave A Tender Moment Alone.