The following has been tested on Sonar6.
Harmony4 needs to be manually configured as a synth in Sonar. To do this follow the steps below:
1. Go to the Cakewalk Plug-in manager window: Process\Audio FX\Plug-in Layouts\.
2. Find Harmony4 in the VST Audio Effects (VST) list.
3. Click the Plug-in Properties button in the VST Configuration group.
4. Click “Configure as Synth” button.
5. Close and exit.
6. Instantiate H4 on an audio track
7. Create a new MIDI track and set the track’s output to Harmony4.
8. Run Harmony4 as detailed in the manual.