Your diaphragm is important for singing, because it hold air in the body, which allows the singer to let out and control the notes they sing, whether high or low, while singing without putting little to no strain on their throat.
After Lennon's death the idea of reunion practically vanished.
Still, Paul McCartney, Star and Harrison got together during their work on "Free as a Bird" (which included the vocals of the late Lennon) for "Anthology 1", released in 1995, and for "Real Love" for "Anthology" 2 ”from 1996.
