Zel-The MIDI Language

The smallest element of musical information generated by Zel is called an event. There are several types of event and these roughly correspond to MIDI events eventually generated on the MIDI cable by the sequencer. Events can be any of the following

Notes
Wheel events (pitch change messages)
Aftertouch (channel or polyphonic)
Control Changes
Patches
System Exclusive Messages

The most important type of event is the note. A group of simultaneous notes is a chord. For convenience Zel allows you to arrange events into tracks. Tracks are familiar to anyone who has used a MIDI sequencer, and in the concept in Zel is much the same. In general it is best to store events destined for the same instrument in the same track. Zel allows grouping of tracks into collections called track-groups. The entire collection of track-groups is called a work. You can see that Zel has an internal hierarchy similar to a musical score.

In the figure above is shown an example of what we mean. Here we have a track-group called all comprising two other track-groups called brass and strings. In turn the brass track-group consists of the two tracks horn and trumpet, while the strings track-group comprises two tracks called violin and cello. In the horn track we show a three note chord and in the violin track a two note chord. The other tracks have a single note. In the Zel realization, the track declaration statement creates the required tracks and track-groups. The text "all" activates the all track-group and notes are then delivered to the correct tracks by using parentheses () to delimit them. You don't have to create chords, tracks or track-groups, all these are optional, but doing so will make your work more structured, more easily understood by those reading your creations and, most important easy to edit. Now we will look at each of these objects in a little more detail.