The Rock n Roll Hall of Fame is in Cleveland Ohio and would be a great stop for anyone heading into Lima for the National.
You might consider buying tickets online beforehand. They only let some many folks per hour in to keep the congestion under control, so having a ticket for a specific time may be a benefit.
You'll need 3-4 hours to see it all, more if you're a music nut!
Maybe the rally team can get us a group discount?