If you can learn the lyrics to the song without reading them.
Hi Paul.........Your post caught my attention because, by coincidence, I've been working on that song (Night and Day) for the last few days now.
Fran IS on the right path. The trick to both playing and singing songs effectively was taught to me many years ago.
Learn the "words" to a song before you learn the actual song. Then....learn the notes. Then....as you're playing or singing, use industrial strength "phrasing" as you think of the meaning of the lyrics.
A great song for practicing that is: The Way You Look Tonight. Listen to both Frank Sinatra and Fred Astaire....masters at song interpretation. And...the queen of interpretation....Eva Cassidy.
Everything else in the video sounds great, and, yes...your saxophone player is really terrific. You might want to study HIS phrasing. His "rides" reek with "phrasing."