Using a plugin with QTractor
To use a plugin with QTractor, do the following:
1) Create a new track via Qtractor's Track -> Add Track... menu. This will present the new track dialog.
2) Set the track's Type to MIDI.
3) Select the Plugins tab.
4) Click the Add button. This will present a dialog showing all the available plugins.
5) If this is the first time you're using the plugins (after installing them), then click the Rescan button.
6) Double-click the name of the desired plugin. For example, below we select the "Cellos" plugin. This will load the plugin, and present its control window. You can close the control window.
7) Click on the Ok button to dismiss the track dialog, and you should see the new track in qtractor's list, with the Cellos plugin added to it.