Jerusalem was written in the early 1900s by Hubert Parry, who set the poem 'And Did Those Feet In Ancient Time', by William Blake to a beautiful melody. The song has been an anthem of sorts in the U.K. for over 100 years. It was used in the London Olympics, and was the opening track on Emerson, Lake & Palmer's 1973 album, Brain Salad Surgery.
James Taylor did a short arrangement of it in his bio 'Break Shot', available as an Audible book. That is where this lesson came from and it includes much of James' stylings and sound. It is challenging and the lesson goes into precise details of thinking of every notes' role in the play.