Seconds after the Handel and Haydn Society stopped playing Mozart's "Masonic Funeral Music" at the Boston Symphony Hall on Sunday, 9-year-old Ronan Mattin was so swept away by the music that he loudly exclaimed — for the whole auditorium to hear — "Wow!"

After a beat, as Ronan's awe-filled "Wow!" echoed throughout the hall, the audience burst into laughter and cheers. So charmed were the Handel and Haydn Society by the child's exclamation that they asked the public to help find him, hoping to reward the sweet sentiment with a trip to meet the artistic director. Audio of the concert was recorded by WCRB, Boston's classical radio station (and part of the WGBH Foundation).

Ronan didn't mean to be disruptive, said his grandfather, Stephen Mattin, who took Ronan to the concert. His grandson, Mattin explained, is on the autism spectrum, and often expresses himself differently than other people.

"I can count on one hand the number of times that [he's] spontaneously ever come out with some expression of how he's feeling," Mattin said.

Mattin said that his sister-in-law saw on television that the Handel and Haydn Society was searching for the "wow kid," and the family, who lives in Kensington, New Hampshire, reached out soon after. The Society has invited them to meet the artistic director, and they are figuring out a date.

Ronan is a huge music fan, his grandfather said. He took the 9-year-old to another concert in Boston a few months ago, and he "talked about nothing else for weeks," he said. Ronan loves taking trips to visit the Museum of Science and the Museum of Fine Arts in Boston, Mattin said, and he was excited for Sunday's concert.

Mozart makes us feel that way, too! Help @handelandhaydn find this child: https://t.co/TsjEQmeSYX pic.twitter.com/FYpXmOT8hl — 99.5 WCRB, Classical Radio Boston (@995WCRB) May 8, 2019

Mattin said he certainly wasn't expecting his grandson's exclamation, but was glad the Society were tickled by it and wanted to connect.

"I had told several people because I thought it was a funny story," Mattin said with a laugh. "About how he was expressing his admiration for the performance and put everybody in stitches."

David Snead, the president and CEO of the Handel and Haydn Society, wrote in a Facebook post that it was "one of the most wonderful moments [he's] experienced in the concert hall."

Ronan's parents, who live about a mile down the road from Mattin, got a kick out of the story, too.

"They weren't too surprised that he should do something to crack everybody up because he's a pretty funny guy," Mattin said.

Mattin said he was touched by the kindness of the other audience members and performers after the "wow" moment, and that the Society reached out.

"You know, everybody's different. Everybody has different ways of expressing themselves," Mattin said. "I think people in general, society's becoming more tolerant or understanding of the differences between people."