Sadly, Andy Williams shouldn't be remembered for this perfect song. The definitive version is the original Henry Mancini arrangement for the fun for the whole family romp, Breakfast At Moon River.
The best version is by a trio consisting of bassist Larry Grenadier, drummer Jorge Rossi, and some doofus on piano, live at The Village Vanguard. To make it even cooler, they play it in the alternating keys of F and D throughout, with a sublime solo piano exploration at the end, which the doofus does at the end of most ballads.
Some of Johnny Mercer's most profound lyrics. The song itself nearly personifies melancholy and hope. At the same time.
Makes me sad just listening to it in my head.