Firts heard of Toots on a John Denver alblum back kn the mid-70’s. I was trying to learn the harmonica at the time (failed miserably). RIP.
...and this catchy tune by “the whistler & his guitar”
Toots Thielemans - Bluesette (1962)
https://www.youtube.com/watch?v=Oi4G6UmYK9U