Uncertainty of vaccine rollout puts summer performance plans in limbo This is when arts presenters usually set their summer schedules, but they don't know what size audiences they can expect. Share Marilyn Keith Daly books the summer concert series at the Hamilton House in South Berwick. She’s planning a full schedule this year, but COVID-related restrictions will determine the size of the audiences. Shawn Patrick Ouellette/Staff Photographer It’s only January, but the window may be closing on the summer concert season unless there’s a big improvement in the rate of vaccinations, said one Maine music promoter.