One of the last times I saw Hairspray, Constantine Rosouli was Link and seemed fine, but after "Welcome to the 60's" ended leading into the dodge ball scene, on walked Curt Hansen, leaving the audience confused when Kate Loprest (as Amber) addressed him as Link.
Apparently, Constantine had food poisoning, but had family coming to see the show and had tried to stay as long as possible, but couldn't continue on. At intermission, they made an announcement that for the remainder of the performance the role of Link Larkin would be played by Curt Hansen, but for the better part of the end of Act One, the audience had no clue who this new Link was.
"Anybody that goes to the theater, I think we’re all misfits, so we ended up on stage or in the audience.” --- Patti LuPone.