To use the drum editor it is required that there is a drum-kit preset assigned to the track. There is an example of this in the freebees demo project. A drum-kit preset is supposed to contain a batch of single key drum presets which then will be shown as lines in the drum editor. If you have created e.g. a library preset for a drum plugin, you can enter the properties dialog for this preset and check the ‘drum kit’ option. Podium will then ask if it should automatically create a set of default GM compatible drum key presets. You can modify these preset objects afterwards.