In addition, they often have difficulty tracking rapid note patterns. However, despite their current limitations, these converters have opened up a new area of interactive performance between instrumentalist and computer in conjunction with some of the software mentioned below. The most common type of software used to link MIDI instruments and microcomputers is a vast array of sequencing programs. The limited number of sequenced notes was increased when small microprocessors, capable of recording and playing back several hundred notes, were added to digitally-controlled analog synthesizers. Current sequencing software allows recording and playback of notes, patch changes, controller information, and even SysEx codes to the limits of the program's memory allocation, usually hundreds of thousand of events.
Sequencers normally organize their information along the lines of multitrack audio recorders.
Information is recorded and edited on individual tracks which are assignable to one or more MIDI channels. Previously recorded tracks can be played back while new ones are recorded. Current software accommodates up to 200 tracks of information. Rhythm is usually organized along traditional musical divisions. Unlike audio tape, sequenced performances can be recorded at a slow tempo and sped up for playback with no change in pitch.