Sarah Jarosz's seventh full-length album, "Polaroid Lovers," embarks on a poignant exploration of fleeting moments and enduring love stories. Rooted in folk-rock, her evocative lyrics and soulful vocals paint vivid snapshots of emotion and introspection. At the Lowell Summer Music Series, Jarosz promises an enchanting performance that captures the essence of her acclaimed new album. Show at Boarding House Park, 40 French St., Lowell. Tickets start at $48. Fees apply.