STUART — Richard Marx wowed his sold-out crowd at The Lyric Theatre on Monday night for more than two hours.

He played his hit songs from the 1990s, his recent releases and some of the songs he co-wrote for others, such as Keith Urban.And he brought along a few friends to help him.

The crowd gasped and cheered when Marx introduced Olivia Newton-John after the first encore to sing "Right Here Waiting" with him. Marx met Newton-John when he was 19 in Los Angeles."You were so fantastic," she told him when she came on stage.

He also sang duets with Matt Scannell of the band Vertical Horizon.

The sold-out crowd was a mixture of older retirees, Gen Xers and a few children with their parents.

Jennifer Roberts of Port St. Lucie came with her sister, Kathleen Flynn."I've loved him forever," Roberts said. Roberts saw him in 1988 in New York and again in Las Vegas about 10 years ago. Flynn got her the tickets for her birthday."He always puts on a great show," she said.

Hobe Sound resident Ted Ford, who came with his wife, Lee, said he has Marx's songs on his iPod. He asked his wife if she wanted to hear a "really great singer."

"He's got some really sweet music," Ford said.Throughout the show, Marx bantered with his audience, referring to them as his friends.

He explained how he came to choose the mullet hairstyle he sported in his early career. Six months before the release of his first album, he saw Mel Gibson in "Lethal Weapon" and thought Gibson looked cool.

"(I thought) I could totally rock that," he joked. "And so I did."

Marx paid tribute to the intimate setting of The Lyric, saying he wanted to return to hear someone else play. At one point, Marx unplugged his guitar and hopped into the aisles to sing.

Marx thanked those in attendance, saying he understood how tight the economy is these days.

"Thank you for coming," he said. "It would be so lame if you didn't come."

Marx autographed a guitar for The Lyric to auction to raise money. He said it was really important to keep places such as The Lyric going.