Since your traveling from Tulsa to Memphis you will pass near the Museum of Automobile http://www.museumofautos.com/ in Morrilton, Arkansas. It’s been many years since I’ve been there but it it had a nice collection. It’s in a state park and there’s a CCC lodge there if your looking for an overnight stay off the beaten path. https://www.arkansasstateparks.com/parks/petit-jean-state-park
In Memphis there’s Graceland (Elvis’s home) https://www.graceland.com/sitemap.aspx, Beal Street, Memphis Music Hall of Fame http://memphismusichalloffame.com/, Nashville has the Country Music Hall of Fame https://countrymusichalloffame.org/, the Lane Motor Museum https://www.lanemotormuseum.org/. It’s winter here so bring warm clothes. Wind chill this morning in NW Tennessee is 16 degrees F (-8 C).
If if you have time to detour come on up to Union City, TN and visit Discovery Park of America https://discoveryparkofamerica.com/.