The Chairs is often labeled a tragic farce. This seems pretty accurate when you look at it from Booker's point of view. The play has structural similarities to both tragedy and comedy:
The Old Man and Old Woman have been living a meaningless life filled with repetition and boredom. However, the Old Man has been working on a great message that will give meaning to existence. Tonight, tons of guests are supposed to arrive and hear the message revealed by an Orator.
Everything seems to be going great. Lots of guests show up, and even the Emperor makes an appearance. Sure, the guests are all invisible, but that doesn't seem to bother the Old Man and Woman. Their dream seems complete when the Orator arrives to deliver the message. The Old Man and Woman are super happy and decide their lives are complete. They both commit suicide, thinking that the Orator will now deliver the long-awaited message. You could also see this double suicide as the Old Man and Woman jumping the gun on the upcoming Destruction or Death Wish Stage. They're OK with the suicide, but it's suicide just the same.
Unfortunately, it soon becomes apparent that the Orator is a deaf-mute. He struggles to speak but the sounds he makes are unintelligible.
The Orator tries to write on a blackboard but those words too are simply gibberish.
The frustrated Orator exits without having communicated the message. It seems that all the Old Man's hopes were for nothing.
The Old Man and Woman have lived meaningless, disappointing lives. However, the Old Man has been working forever on a great message that will reveal to everyone the meaning of it all. He and the rest of humanity will soon be saved when his great message is delivered by the Orator.
The guests begin to arrive to hear the all-important message. However, these folks are invisible to everyone accept the Old Man and Woman. The audience is left to wonder whether the elderly couple is just imagining it all. Are they crazy or can they see things that we can't?
For a moment, the mystery seems to be dispelled. The Orator arrives and he's actually a real person. Well, he's played by a real actor at least. The Old Man and Woman are incredibly happy. Here, though, the play veers drastically from most comedies. The couple is so confident that the message will be revealed that they both commit suicide. But the Orator, a deaf-mute, is incapable of communicating with the crowd. The message only comes out as gibberish. In the end, nothing comes to light. Unless, of course, the message the whole time was that the universe itself is gibberish. Perhaps it's all an unsolvable mystery, and we're supposed to take some kind of comfort in that. Either way, the answer to it all remains hidden from view.