SCARBOROUGH, Maine — The first of three festival-style concerts at Scarborough Downs on Tuesday resulted in a few arrests and cases of heat exhaustion, but no major problems, according to Police Chief Robert Moulton.

“It went relatively well. We had had some medical issues, a combination of dehydration, maybe a little too much high-energy dancing,” Moulton said.

The evening was cool and overcast, but Moulton said about 17 people were treated at a medical tent at the concert and seven were taken to area hospitals.

Moulton said there were some arrests and ejections for alcohol and drug violations.

“It was nothing of any significance,” he said.

The Under the Influence of Music Tour, headlined by rappers Wiz Khalifa and Mac Miller, drew an estimated 6,000 fans to a stage set up outside the racetrack. Staffers at the site said the music began around 5:30 p.m., and as rapper Chiddy Bang played a set about an hour later, vehicles flowed into parking lots from Route 1 and Payne Road entrances without causing any backups.

Traffic was congested on the track access road leading to Payne Road after the show, but Moulton said town roads were unaffected.

Moulton said the concert was staffed by nine local police officers working with security staff provided by the promoter, Waterfront Concerts.

Waterfront Concerts is staging two more shows at the track this summer. On Aug. 10, seven acts headline the metal Oxxfest show. On Sept. 7, classic rockers ZZ Top and Lynyrd Skynyrd will perform.

The company also stages shows at the Waterfront Pavilion in Bangor, and Moulton said their experience with concerts provided a level of comfort for him and his staff.

“A lot of planning has gone into it,” Moulton said. “We have been working with the promoter.”

Last summer, Scarborough Downs hosted a country-western show headlined by Brad Paisley and Moulton said the department learned about traffic flow problems and noise complaints from that show.

This year, the stage has been shifted to face the Payne Road entrance instead of Route 1, with woods providing a sound barrier. Moulton said officers will also be more vigilant about traffic using southbound Payne Road to enter Scarborough Downs because online directions guide drivers to Maine Turnpike Exit 45 at the Maine Mall, instead of Exit 42 at Haigis Parkway.

Before the summer concerts began, councilors also amended the town mass gathering ordinance to allow more than five mass gatherings and reduce permit fees for companies applying for more than one permit. The Downs can hold up to 11,000 fans for shows.

For any gathering of 1,000 or more, organizers must post a bond of 120 percent of the cost of municipal services needed for safety and crowd control. Organizers are also required to alert hospitals within 25 miles about their events.

Moulton said the town and promoters are also working with an independent sound engineer to get a more complete picture of how sound travels through the area around the venue.

“Simple decibel metering may not show a complete picture,” he said. “Sound can travel in varied ways.”