L.L. Bean hosts free outdoor concerts featuring internationally-known acts in Discovery Park (next to the Flagship Store) each summer. Past performers include Brandi Carlile, Nickel Creek, the Mavericks, Andy Grammer, Roseanne Cash, Trombone Shorty and Orleans Avenue, Toad The Wet Sprocket, and many more.
FMI: http://www.llbean.com/llb/shop/513045?nav=sr&term=concert+series