Conversation so far:
When was Bob Dylan's Never Ending Tour?
The Never Ending Tour is the popular name for Bob Dylan's endless touring schedule since June 7, 1988.
How long did Bob Dylan's Never Ending Tour last?
The Never Ending Tour is the popular name for Bob Dylan's endless touring schedule since June 7, 1988.

Question: What songs did he sing on this tour?
Self-contained rewrite: What songs did Bob Dylan sing on his Never Ending Tour?