On The Ocean music festival takes place August 7-9, 2026 in Portland, Maine, featuring headliner Guster in an intimate lineup focused on rock, acousmatic, and folk rock genres. This three-day festival showcases American artists across multiple rock subgenres, making it an ideal destination for fans of alternative and folk-influenced rock music. The festival's concentrated artist roster promises an focused musical experience for attendees seeking quality rock performances in Maine's vibrant music scene.