Tracker (music software)

Music trackers (usually referred to simply as trackers) are a class of music sequencer software used to create and edit module files; they allow the user to arrange notes stepwise on a timeline across several monophonic channels.

A tracker's musical interface is traditionally numeric: both notes and parameter changes, effects and other commands are entered with the keyboard into a grid of fixed time slots as codes consisting of letters, numbers and hexadecimal digits. Separate patterns have independent timelines; a complete song consists of a master list of repeated and concatenated patterns.

Recent trackers have departed from module file limitations and advantages, adding other options both to the sound synthesis (hosting generic synthesizers and effects or MIDI output) and to the sequencing (some degree of MIDI input and recording), almost becoming general purpose sequencers with a different user interface.