Texas born country singer John Rich has written a theme song for John McCain, and the singer will be one of the performers at the GOP convention. On the other side of the aisle, singer Joss Stone is reportedly creating a campaign song for Barack Obama. Music as part of political conventions dates back to the 18th century. This year, the Republicans are expecting convention performances by Gretchen Wilson, Cowboy Troy, Charlie Daniels, the Beach Boys and Sammy Hagar. The Democrats look forward to performances by Willie Nelson, Black Eyed Peas, Kanye West, Jennifer Lopez, and Melissa Etheridge (and Rage Against the Machine, in a coinciding Iraq war protest rally). But what does music say about the candidates? The Takeaway listens to music from past conventions and previews the music to come.