The brightness of the moon from Earth depends on where the moon is in its perpetual journey around the planet.

You’re on the Sound Beat.

It orbits Earth every 29.5 days, and during that time it’s lit from various angles by the sun. It’s at its brightest when it is 180 degrees away from the sun from our perspective (picture the sun, Earth and moon in a straight line). At that time, the full half of the moon’s surface facing the sun is illuminated and is visible from Earth. And that’s a full moon, friend. The moon absorbs much of the sun’s light, but about 7% is reflected towards the Earth. That’s why the moon appears to shine, or glow, if you will.

If you don’t know by now, you’ve been listening to the jazz standard Moon Glow. Art Tatum recorded  version, Cab Calloway, Benny Goodman, Ethel Waters, Billie Holliday, Bing did one…you get the idea. But before all of that Joe Venuti and his Orchestra recorded it in 1933 for Columbia.