Uncanny X-Men (1981) 294-A

"X-Cutioner's Song, Part 1 of 12: Overture"

Lil Chaney gives a concert in the Park as she tries to send out a message of unity between humans and mutants by allowing Professor X to address the crowd, which has mixed emotions about the message. But there are some whose emotions are clear about Professor X as Cable moves in to assassinate the Professor. Meanwhile, Caliban turns on X-Factor as he attacks and kidnaps both Jean and Scott. The Four Horsemen of the Apocalypse arrive at the concert and battle with the X-Men but in the end, the X-Men win the day.

Continues in X-Factor (Vol 1) #84.