and everything under the sun is in tune, but the sun is eclipsed by the moon.

“I don’t see it as a riddle. The album uses the sun and the moon as
symbols; the light and the dark; the good and the bad; the life force as
opposed to the death force. I think it’s a very simple statement saying
that all the good things life can offer are there for us to grasp, but
that the influence of some dark force in our natures prevents us from
seizing them. The song addresses the listener and says that if you, the
listener, are affected by that force, and if that force is a worry to
you, well I feel exactly the same too. The line ‘I’ll see you on the
dark side of the moon’ is me speaking to the listener, saying, ‘I know
you have these bad feelings and impulses because I do too, and one of the ways I can make direct contact with you is to share with you the fact that I feel bad sometimes.”—Roger Waters