What is a step sequencer

Why sixteen

Most music is counted in bars of four beats. Cut each beat into four and a bar is sixteen steps, each a sixteenth note. The beats fall on steps 1, 5, 9 and 13, and the off-beats between them on 3, 7, 11 and 15. Sixteen is fine enough for nearly any drum pattern and few enough to see at once.

How to read one

Each voice, a kick or a snare or a hat, has its own row of steps. A step that is on sounds when the playhead reaches it. The playhead crosses the row at the tempo, and at the end of the bar it starts again. A pattern is no more than which steps are on.

Swing moves every second step a little late, so the bar leans. On Beep Boop the SWING knob sets how far.

Where it came from

Roland's CR-78, in 1978, was the first drum machine that let people write, save and replay their own patterns. Two years later the TR-808 put a row of sixteen keys across its panel, one for each step, lit as the pattern played. The TR-909 followed in 1983. That row of sixteen is the step sequencer most people mean.

On Beep Boop

Beep Boop has sixteen step keys, in two rows of eight, with a lamp above each. The voice dial chooses which of eight voices the keys show: KICK, SNARE, CLAP, HAT, OPEN, TOM, RIM and PERC. The window above shows all eight at once as dots, sixteen across and eight down, so the whole beat can be read without turning the dial.

• Patterns to try, each drawn on the sixteen keys.
• Tempo by genre, for where to set TEMPO.

Sources

• The definition: Music sequencer, Wikipedia.
• The machines: Roland CR-78, Roland TR-808 and Roland TR-909, Wikipedia; The TR-808 Story, Roland.
• Swing: Greg Scarth, Roger Linn on swing, Attack Magazine.

More patterns