Sorry, that headline makes it sound like he did a rendition of “Happy Birthday”. Stereogum reports: “James Taylor guested on Jimmy Kimmel Live! last night for the late night host’s 50th birthday celebration. Taylor’s appearance was a surprise, and he broke out his 1970 classic “Sweet Baby James,” performing it alongside a cellist and accordionist. Ben Affleck also appeared on the show and presented Kimmel with a live action short inspired by a comic book Kimmel wrote as a kid. The short was co-produced by J.J. Abrams and John Hamm plays a leprechaun. Watch below.” And weep.
https://www.youtube.com/watch?time_continue=72&v=BeZUTXzX6M8
https://www.youtube.com/watch?v=t8Jq6NqCQ1o