The term "Instrument Editor" in Music Maker is used for the plug-in interface of a VST/software instrument. So, it would only be relevant to MIDI tracks. You can reach it by right-clicking on a MIDI object and choosing "Instrument Editor" from the context menu. This will open the GUI for the software instrument assigned to that particular project track. Alternatively, especially if there's no MIDI object in that track yet, you can also click the small cog icon in the track header, next to the pictogram that visually represents that track, and between the up and down arrows that allow you to toggle through the preset bank for that particular software instrument.
Hi ralfaro (nice name by the way), thanks for that, see it now. Seems that all the samples in the 2 demo projects supplied don't use a VST/software instrument that I have. Only when I use a sample that is created from a VST I own, do I see the option.
Yeah, that sounds about right. There's indeed no use of VSTis in the current demo projects. It's all audio loops. In most cases, you will probably be able to easily tell apart the audio and MIDI objects just by looking at them. The former will show the typical, consistent waveform patterns, while the latter will show little distinct dots or lines, representing the MIDI notes in matrix view. If the object is long enough and/or the vertical zoom level is high enough, you should also see the object name at the bottom. Unless it was specifically changed, it should be *.HDP for the audio loops, and *.MID for the MIDI objects. (Or maybe "MIDI REC" for MIDI objects created via recording.)