Today begins a new edition of our blog feature “Variations on a Theme,” in which we devote digital ink to a topic that fascinates us. This week, it’s soul music.

In honor of the late Don Cornelius, who passed away suddenly and sadly last week, we’re devoting a whole week to soul music. If you haven’t read Jake Austen’s story on Soul Train in Chicago, you can read it here. And here’s some early Don Cornelius memorabilia, courtesy of Tom Weinberg, via Michael Miner.