Double bill by two singer-songwriters. Heaton is an NYC-born, Milwaukee-based pop-folk singer and pianist who cites Peter Gabriel, Tori Amos, and the Indigo Girls as her main influences. Originally from Houghton, Mari is an Americana roots artist whose songs weave complex chord progressions with heart-wrenching lyrics. 7–9 p.m. (doors 6:30), Chelsea Depot, 125 Jackson St., Chelsea. $20 suggested donation at the door. onthetrackschelsea.com.