The WS has two dynamic velocity switches per voice A-E and by using these coupled with an external computer sequencer or keyboard you are able to access up to 15 voices at any one time (although that is the theory).
In practice by making use of one dynamic switch you can easily compress most existing songs down into using three or four tracks, this leaving one or two spare for solo or melody playing. However, it must be said that you will of course loose expression of velocity and some polyphony, on some multiple voices.
Using this method both the main voice and one of the dynamic switch voices will sound simultaneously thus giving for example Strings and Piano on ONE track. Some of our demonstrations have used this technique, thus providing a full accompaniment whilst leaving one or two voices for the free melody.
A number of song or sequences in the disk library make use of this to quickly switch or mix sounds.