A 3,500-seat concert hall and track-and-field facility with a 20,000-square-foot sports research lab are under construction at Boston Landing in Brighton.

A groundbreaking ceremony was held Monday morning for The TRACK at New Balance, which has a projected fall 2021 completion date.

AEG Live leased 41,000 square feet of ground-floor space in the building last month from NB Development, the real estate arm of New Balance that owns the 15-acre mixed-use development. AEG Live’s Bowery Presents affiliate, which operates The Sinclair in Cambridge and Royale and Great Scott in Boston, will manage the Brighton facility, which will be named at a later date.

New Balance Chairman Jim Davis recounted the 15-year process of acquiring and redeveloping the parcels behind his former offices into a new headquarters and additional office and lab space, 300 apartments, retail and restaurant space and a planned 200-room hotel.

“This was really not an attractive site,” Davis said. “We were looking at a depressing 15-acre wasteland contributing nothing to the betterment of the community.”

Davis credited the $20 million Boston Landing Commuter Rail station completed in 2017 with contributing to the project’s success. NB Development paid for the project.

With seating capacity for 5,000 spectators, the athletic complex will include a 200-meter track used for training by New Balance’s running team, a turf field and a 20,000-square-foot sports research lab that uses motion capture technology and specialty treadmills to analyze athletic performance and influence athletic product development.

The TRACK at new balance is being designed by Elkus Manfredi Architects and will be constructed by John Moriarty Assoc..

The 1.9-million-square-foot Boston Landing development includes the Lantera apartment tower, training facilities for the Celtics and Bruins, New Balance’s headquarters and office and lab space leased to Bose, Proteostastis, Smartlabs (formerly Mass Innovation Labs) and Global Atlantic Financial Group. The site has a 250,000-square-foot office and lab development site at 60 Guest St. seeking an anchor tenant.