Watch: PETER CRISS Sings 'Happy Birthday' To JOHN 5 At ROB ZOMBIE's New Jersey Concert

Original KISS drummer Peter Criss surprised John 5 by leading the audience in a spirited "Happy Birthday" sing-along to celebrate the guitarist's 51st birthday during ROB ZOMBIE's concert in Holmdel, New Jersey Sunday night (July 31).

Prior to launching into the song "Shake Your Ass-Smoke Your Grass" at the PNC Bank Arts Center, Rob addressed the crowd: "Maybe you know, maybe you don't know, today is J5's birthday. As you know, J5 is a really big KISS fan, so I thought to myself, 'What can I get John 5 for his birthday that he doesn't already have?' I went out and got him an original Peter Criss… You don't have this at home, J5, I don't think."

Criss then came out on stage and told the audience: "Hey, listen, it's Johnny's birthday, so I wanna say I'd like you all to sing with me happy birthday to Johnny 5." Everyone happily obliged and a visibly touched John 5 gave Criss a hug before the legendary rocker walked off.

Criss and John 5 are longtime friends, with Peter having made a guest appearance on the guitarist's latest solo album, last year's "Sinner".

John 5, whose real name is John William Lowery, spoke about the collaboration a year ago during an appearance on Sirius XM's "Trunk Nation With Eddie Trunk". He said at the time: "Peter Criss is playing drums on the song 'Georgia On My Mind', which is the last song on the record. And I'm telling you… This guy… Barry Pointer, my producer, flew out to Peter's house, set up a couple of mics. Now, this is a jazz type of song, and Peter is known for that jazz feel he has. I shit you not, he sat behind those drums, played two takes. Barry's mouth was dropped open. Wait till you hear this. I mean, it was perfect."

John 5 continued: "It's something you can't teach, is this feel and this vibe. And he nailed it in two takes. And Barry was, like, 'Well, what do we do now?' It took him, like, literally probably eight minutes. And it was just perfect. He was, like, 'There's nothing else we can do. That was perfect.'"

In a 2014 interview, Criss said that he had been working with John 5 on material for a new rock solo album, which he promised would be "heavier" than the stuff he had done in the past.

Criss first left KISS in 1980. Since then he's worked with other bands and released solo albums. He teamed up with KISS again for a reunion tour in the 1990s and most recently in 2004. He was replaced by Eric Singer.

In addition to playing drums in KISS, Peter also provided lead vocals for a number the band's most popular and memorable songs, including "Beth", "Black Diamond" and "Hard Luck Woman".

Criss, who was known as "Catman," released his last solo CD, titled "One For All", in 2007. Peter produced the album himself for the first time, and was joined by guest musicians that included keyboardist Paul Shaffer and bassist Will Lee of "Late Night With David Letterman". The album featured a range of styles, from rock and jazz to blues and Broadway, and included covers of "What A Difference A Day Makes" and "Send In The Clowns".

Criss, who turned 76 last December, played what was being billed as his final U.S. concert in June 2017 at the Cutting Room in New York City.

This past May, Peter joined Australian rockers SISTERS DOLL on stage during their concert at the Cutting Room to perform three songs.