‘Who Knows’ is on the 1953 trio album ‘The Duke Plays Ellington’. The material was later released under the album title ‘Piano Reflections’. Amazingly, Ellington made recordings from 1927 to 1974 and he always moved the genre forward. Consider his trio recordings essential listening.
‘Who Knows’ has the “Ellington sound”. It begins with a series of dominant chords a fifth apart moving down in whole steps. The ‘B’ section has displaced chords in the left hand punctuating a repeating melody. The example to the right is one of the many ways Ellington embellishes pauses in his melodies.