Retriggering is a tracker technique in which a sample is replayed a set number of times within a certain timeframe.
Traditional music trackers cut time into "ticks" based on the system clock of the hardware the software is running on.
This allows the musician to visually organize time in a gridwork of cells in which to set these events into motion, and thus decide the overall tempo of the music.
This "time signature" can be altered programmatically throughout the piece of music, allowing tempo to rise, shift, swerve erratically or any combination of these as the musician sees fit.
For tracker musicians working at very slow speeds, the need to escape the confines of this time-grid is often apparent.