Medford musician Alex Cumming is presenting a concert in support of the Greater Boston Food Bank, which operates the Mystic Community Market on Mystic Avenue in Medford in partnership with the Malden YMCA. Alex says, "Let's make this a hunger-free holiday season. This year is especially hard due to lost income and jobs due to COVID-19. Please donate and help individuals and families in need!" Cumming, music director at the Unitarian Universalist Church of Medford, is a traditional singer, accordionist,…