The DJ industry was hit hard when the COVID-19 pandemic wiped out all of their summer gigs, but The DJ Firm in Chicago has kept the music going by designing mobile, pop-up DJ set.“We just decided that we still wanted to make an impact (since) music is food for the soul,” said DJ Eric Sampson. Initially, Sampson and his business partner Sye Young started popping up at grocery stores to start social distance dance parties for everyone waiting in line. They soon started showing up at public parks and birthday car parades.“When we get done at a park, and we get in the van, we’re just so excited about how fun it was to bring joy to people’s faces,” Young said. The DJ Firm’s free pop-up dance parties are part...