Hit the Stax Museum, Sun Records Studio tour, and the Rock and Soul Museum tour. Graceland is tomorrow. Some overlap between the 3 today, but in a cool way.
We did Nashville and hit the country music museum and it was a great spot, I thought the extra to see RCA studio B really added to it. Johnny Cash museum is a little much unless you're a huge fan. Just going on the main strip and hearing some music is a fantastic time, if a bit crowded.