A beatgraph visualizes the energy content of a song in 2 dimensions. From top to bottom the content of one bar is shown, while, from left to right, all bars are placed next to each other. Bright pixels indicate high energy waves (typically the bass drum), while dark pixels indicate low energy.

The picture shows the pattern visualization of a simply 4/4 drum loop. Although at first it looks confusing it does show the entire song in one picture. 4 broad horizontal bands catch the eye. Each band represents a beat.

Some features of beatgraphs

In summary: in the blink of an eye, the DJ sees the overall structure of a song: where are the breaks ? Where are the buildups ? Where are the bass drums ? What rhythm does the song have ?

A full description of beatgraphs can be found at Beatgraphs: Music at a Glance