I am really amazed about the demo of the Lowrey MX-1. I remember as a child there was somebody across the field in the adjacent suburb who had a very expensive organ in the early 1980s. Maybe it was this organ, I remember I was totally fascinated about it at that time. Later I got a Yamaha Electone (which my piano teacher probably wasn't too happy about).
I wonder how they were able to achieve such a relatively realistic trumpet and trombone sound in 1980. I don't see how they could have used samples yet - the world's first sampler, the Fairlight CMI, had just been released in 1979 and consisted of a huge computer that couldn't have been incorporated in such an organ. So it must have been an incredibly good imitation by frequency modulation technology or similar.
I checked a PDF brochure also of the later model Lowrey MX-2, which obviously was released around 1989. In that brochure, it is mentioned that PCM voices, i.e. samples, were used for all voices.