On Sept. 16, 2018, Ethan Slater braced himself for the final performance of “SpongeBob SquarePants.” The Nickelodeon musical had been open on Broadway for nine months, and it received generally positive...

BEVERLY HILLS, Calif. — Imagine a Disney cartoon that melts into a live musical. That’s just what ABC is planning for Nov. 5. And if it sounds a little bit remarkable, it is. The hybrid will commemorate...