Down By Riverside, a new Medford nonprofit organization providing community connectedness through music, performance and education, presents its third Spirit of Music Potluck Concert — celebrating mothers on Mother's Day! Spirit of Music Potluck Concerts use music and food to create feelings of connectedness and community. The music and performers are curated to engage the spirit, educate participants, and to transport the listeners to a safe place. For this concert, the Willie J. Laws Band will be the special guest…