Broadway insiders welcomed “Glee” star Darren Criss to the Great White Way with a cocktail reception Jan. 9 at the Darby, and Criss returned the favor with a mini-concert for the revelers.

Criss has replaced Daniel Radcliffe in “How to Succeed in Business Without Really Trying,” but it’s only a three-week stint, with Nick Jonas to follow him into the revival. Said Criss of his Broadway gig: “There’s me the fanboy and me the actor. As an actor, when I was presented with this opportunity, I was like, absolutely. As a fanboy, I thought, Darren Criss as J. Pierrepont Finch? I don’t know about that.”

Criss took to the stage with the five-piece Chinatown All-Stars and his Johnnie Walker Black on the rocks to sing “Part of Your World” from “The Little Mermaid” (assisted by Alan Cumming’s well-timed shouts of “feet” and “street”) and closed things out with “Teenage Dream,” calling it “a nice little button for the evening before we continue with the drinks.” — Rob Voris