Returns a FoscDescendants.
Descendants of a component.
Descendants is treated as the selection of the component’s improper descendants.
[ ]
Example
a = FoscVoice([FoscNote(60, [1, 4])]);
b = FoscDescendants(a);
b.items.collect { |each| each };[ FoscVoice([ ], 'Voice', false), FoscNote(FoscPitch("C4"), FoscDuration(1, 4)) ]
b.last;FoscNote('C4', 1/4)
b.component;FoscVoice([ ], 'Voice', false)