lv2dynparam is a LV2 plugin interface extension that enables plugin
parameters to appear and disappear (i.e. number of voices). It also allows
nested grouping of parameters. Groups can be used for things like ADSR
abstraction, i.e. group of 4 float parameters.

The extension consists of a header describing the extension interface
and libraries, one for plugins and one for hosts, to expose functionality
in more usable, from programmer point of view, interface.

This requires lv2.