“Rainbow Jeff” Rawitsch hosts Tufts University’s student-run a cappella groups Enchanted, the Jackson Jills, sQ!, and the Amalgamates in a Family and Children’s Concert of tunes for music fans of all ages. The program will culminate in a sing-along of “Rainbow Connection” with Rich Stillman, banjo. Free to the public with no tickets required; also viewable via Tufts Music Live Streaming.