BANGOR — Waterfront Concerts promoter Alex Gray promised a large gathering of business people that 2015 will be the “most amazing year yet” for what has become one of the city’s top attractions.

Gray delivered the keynote address during the Bangor Region Chamber of Commerce’s annual breakfast Wednesday morning at the Cross Insurance Center. Chamber officials said about 350 business owners, area politicians and municipal officials attended the breakfast, making it the largest to date.

Waterfront Concerts has already confirmed 10 acts for the approaching concert season, Gray said, and the five-year-old endeavor will start announcing this year’s shows in the near future.

“You can expect an announcement every Monday or Tuesday for the next few months,” Gray said. Waterfront Concerts already has announced two shows at the Bangor Waterfront — Rise Above Fest on May 9 and Nickelback on Aug. 19.

Since its first season in 2010, Waterfront Concerts has held 75 events along the banks of the Penobscot River. Peer-reviewed studies by University of Maine economist Todd Gabe found that in the first four seasons, Waterfront Concerts contributed an estimated $47.5 million to the Bangor area economy, and that contribution has grown each year.

In the 2015 season, Waterfront Concerts is expanding its offerings in southern Maine, bringing more concerts to the Maine State Pier stage in Portland.

Gray told the Bangor chamber that this move was meant, in part, to protect the future of Bangor’s concert stage.

“This could all be gone tomorrow,” if a competing entertainment organization set up a large outdoor venue in the state, Gray warned, as he has in the past.

Gray said he and Live Nation, the entertainment conglomerate that merged with Ticketmaster in 2010, “took a shot” on Bangor because Gray wanted a venue close to his hometown of Old Town.

“I wanted this to be what I hope it has become,” Gray told the chamber, which represents 21 Bangor-area communities and more than 830 members.

Gray credited fan and community support for the success of the venue, as well as the city for “letting a kid start a concert company.”

“We can put on concerts, but if no one shows up it doesn’t matter,” Gray said.

He urged the crowd to continue pushing for investments and development in the Greater Bangor Area, and encouraged city officials and business people to continue striving to draw people from across the state and region to the casino, symphony, theater, Little League World Series, snocross, color runs and beer festivals.

“I’m excited for what the next five years hold,” Gray added.