Bono sings cabaret in New York
On Sunday night U2’s front man, and part time New York resident, Bono, gave customers at Bemelman’s Bar, at the Carlyle Hotel, the shock and treat of their lives when he joined the joints usual musicians on stage.

The Dublin music legend stayed up on stage and sang a couple of numbers with singer Jim Caruso and pianist Billy Stritch.

Caruso told the Huffington Post “Bono walked in. It was impossible not to recognize the guy – the glasses alone gave him away!”

They were seated in the corner, where they rocked, bopped, swayed and snapped. He kept giving me the thumbs-up when he'd like a tune and singing along quietly."

The musicians were performing songs from the Great American Songbook, songs that Bono knows well.

Before leaving the bar Bono joined the pair in the harmonies of “I’ve got you under my skin”, a tune he recorded with Frank Sinatra, in 1993.

Caruso said “The room was stopped cold.

"Just another miraculous Bemelmans moment! After the last note was crooned, Bono flew out the door, waving to everyone. Billy looked at me and said dryly, 'Well ... that happened!'"

Here's the audio of Bono singing "I've Got You Under My Skin" with Frank Sinatra: