Slinging sundaes and Be-Bop-a-Lula burgers, the singing waiters at Ellen’s Stardust Diner near Times Square made vocal warm-ups out of their food orders — “Do you want waffle fries with that?” from the diaphragm — and practiced lip trills while running for things like ketchup. Their framed photographs lined the walls, “Stardusters” given the billing of Broadway headliners.

The diner is a kitschy place with a chrome-clad warmth that workers said was genuine. The quirky restaurant was to the singing workers a haven where Broadway hopefuls did more than belt out show tunes standing on the back of banquettes, several said in interviews. It was a place where they could make a living while striving for stages not upholstered in red vinyl.

But more than a year ago, that began to change. The owner, Ken Sturm, brought in a new management team. Once-overlooked infractions, like sipping hot water on the restaurant floor to soothe tired vocal cords, were penalized, waiters said. The ability to take time off if a server landed an audition or a role, and return to a job at Ellen’s, was no longer guaranteed. A tip bucket was taken away until workers complained.

“It started to feel less like this was my safe place and more like this was something that was eating away at me a little bit,” Lisa Kranz, 27, said. “But I still got to go to work every day with my friends — and sing.”