This photo shows one of the greatest bands of all time, Pink Floyd, playing a concert at Merriweather Post Pavilion in Columbia, Maryland, just outside Washington, DC. This was either June 20th or 21st of 1973.
Roger Waters, David Gilmour, Nick Mason, and Richard Wright made up the psychedelic British rock band and that spring they released what possibly is the best rock album of all time: The Dark Side of the Moon.

Source: U.S. National Archives
The picture above shows the long-haired Gilmour in his mellow, tranced way of strumming guitar while Roger Waters hair-covered face is in the background as he lays down a hypnotic bass line.
According to setlist.fm, below were the songs they played those two nights.
- Obscured by Clouds
- When You’re In
- Set the Controls for the Heart of the Sun
- Careful with That Axe, Eugene
- Echoes
- Speak to Me
- Breathe
- On the Run
- Time
- Breathe (Reprise)
- The Great Gig in the Sky
- Money
- Us and Them
- Any Colour You Like
- Brain Damage
- Eclipse
- Encore: One of These Days
And here’s the second night.
- Echoes
- Obscured by Clouds
- When You’re In
- Childhood’s End
- Careful with That Axe, Eugene
- Speak to Me
- Breathe
- On the Run
- Time
- Breathe (Reprise)
- The Great Gig in the Sky
- Money
- Us and Them
- Any Colour You Like
- Brain Damage
- Eclipse
- Encore: One of These Days