Let's imagine Madonna wants to dedicate to cinema and other ventures. Many years later, she's back to the stages but with no new studio album, so she will perform a greatest hits tour, something no one would have ever thought she would do in her entire career.
Every segment is decade-related, full of music samples of other artists successful in that particular decade (80's, Michael Jackson; 90's, Spice Girls; 2000's, Britney Spears; 2010's, Rihanna, for instance) and so on. The only disadvantage would be that the setlist would consist on many medleys.
ACT 1:
1. "Intro": Some clip of her early years with an audio of her young voice from the seventies.
2. "Everybody"
3. "Burning Up"
4. "Like a Virgin" / "Material Girl"
5. "Live to Tell" / "Open Your Heart"
6. "Like a Prayer"
7. "Vogue"
ACT 2:
6. "Interlude": A clip of pieces of news about the impact and controversies Madonna has had along the eighties (HIV, LGTB rights, etc.), introducing the nineties
7. "Erotica" / "Deeper and Deeper"
8. "Rain"
9. "Secret"
10. "Take a Bow"
11. "Frozen" / "The Power of Good-Bye"
12. "Ray of Light" / "Beautiful Stranger"
ACT 3:
13. "Interlude": A clip with controversies and reception of Madonna's nineties work, introducing the new millenium.
14. "Music"
15. "Don't Tell Me"
16. "Die Another Day" / "Hollywood"
17. "Nothing Fails"
18. "Hung Up" / "Sorry"
19. "Give It 2 Me" / "Celebration"
ACT 4:
20. "Interlude": A clip with Madonna's new ventures and how new pop artists have disappeared (would be epic lol) and media ageism against her.
21. "Girl Gone Wild"
22. "Masterpiece"
23. "Living for Love"
24. "Ghosttown"
25. "Song request": every time Madonna confirms a new date for her tour, she offers a poll on the Facebook wall of that event so fans can vote what song they want to be performed there. Obviously they can only choose from songs not included on the setlist.
26. "Interlude": A clip with Madonna's vision on how the world has changed and the incertainties of the future.
27. "Holiday": it features an incredible backdrop full of pics, videos, and art about artists (musicians, dancers, actors, actresses, writers, directors, etc.) from all around the world and eras.
This obviously will never happen, but dreams are free