Metro

2nd. Ave. Subway singer’s big gig

There’s light at the end of the tunnel for Manhattan’s construction-site crooner.

The Second Avenue Subway hardhat famed for belting out lunch-break standards hit the legendary Blue Note in Greenwich Village last night in his after-hours debut.

Gary Russo, 50, traded in his battered Carhartts for a swanky black suit to churn out “Mack the Knife” and “Summer Wind” in front of an adoring crowd of 200.

“I just witnessed a man’s dream come true,” said audience member Jennie Rosenberg, 36, of Manhattan.

After the performance, Russo said, “I really just wanted to pay tribute to all of my favorite artists who’ve been here before. Music has gotten me through some dark moments.”

While thrilled with his Blue Note gig, which was arranged by the TV show “Inside Edition,” Russo said he left his heart on Second Avenue.

“I’m really just focusing on working the audiences at my site from 12 to 12:30 every day,” he said.

But Russo revealed that he’ll be relocated to another construction site in a few weeks.

Not wanting to taint his magical stint on Second Avenue, Russo said he won’t be bringing his songbook to the new location.

“I’m just humbled by the whole situation,” he said.

selim.algar@nypost.com