When someone says, “Well, I guess I'll have to go to face the music,” it does not mean he is planning to go to a concert. It is something far less pleasant, like being called in by your boss to explain why you did this or that, and why you did not do this or that. Sour music, indeed, but it has to be faced.
The phrase “to face the music” is familiar to every American, young and old. It is at least 100 years old.
The first information comes from the American writer James Fennimore Cooper. He said—in 1851—that the expression was first used by actors while waiting in the wings to go on stage. After they got their cue to go on, they often said, “It's time to go to face the music.” And that is exactly what they did-face the orchestra which was just below the stage.
An actor might be frightened or nervous as he moved on to the stage in front of the audience that might be friendly or perhaps unfriendly, especially if he forgot his lines. But he had to go out. So, “to face the music” came to mean having to go through something, no matter how unpleasant the experience might be, because you knew you had no choice.
The other explanation comes from the army. Men had to face inspection by their leader. The soldiers worried about how well they looked. Was their equipment clean—shiny enough to pass inspection? Still, the men had to go out, and face the music of the band, as well as the inspection. What else could they do?