The New York-born musician Leon Michels used to be a member of bands like Sharon Jones’ Dap-Kings, and he co-founded Dan Auerbach’s side project the Arcs. These days, Michels collaborates with a number of different artists, and he also makes lush retro-funk with El Michels Affair, his own band. Last year, Michels was one of the producers of Clairo’s album …