The Boston Landmarks Orchestra exists for one purpose: putting free, professional orchestral music where everyone can reach it. Its summer home is the Hatch Shell on the Charles River Esplanade, where the full orchestra performs on Wednesday evenings, with additional performances scattered through Boston’s neighborhoods across the season.

These concerts are engineered for openness in every sense — no tickets, picnics and dogs welcome on the lawn, ASL interpretation at Hatch Shell programs, and haptic vests on select nights so Deaf and hard-of-hearing listeners can feel the music. Bring a blanket and arrive early for a good patch of grass; the riverfront at dusk does the rest.