[sdiy] An Elementary Question: Synths vs Organs

[Tom Wiltshire]

On 21 Feb 2009, at 22:18, Matthew Smith wrote:

> Hi Folks
>
> Where do organs start and synths end, and vice-versa?
>
> I would like to exclude modern, all-digital gear from this  
> discussion as such things probably muddy the waters in this context.
>
> The impression that I get is that an organ generates all the tones  
> at once via a top-octave generator, divides them down and then adds  
> them to a mix as notes are activated.  Then, with a synth, we have  
> one or a number of tone generators* of definable pitch with no  
> fixed note assignment - this being dynamic when notes are activated.
>
> Is my thinking correct?

Yes, in general terms, I'd say it is.
Early synths were monophonic and used one voice which was assigned to  
the note currently being played. Later synths with more voices  
generally followed the same pattern, assigning voices to notes played.
Instruments like the Korg PS series synths confuse things by being  
completely polyphonic - eg, one voice per note. Similar confusion is  
caused by most of the "string synth" instruments which are much  
closer to the divide-down organ technology and retain the complete  
polyphony that goes with it. The Polymoog is another cross-over  
example. As mentioned already, many top-end 1970s/80s organs included  
a manual that was basically a monophonic synth, which also helps  
confuse things, although sticking a synth in the box with a organ  
doesn't stop the synth part being a synth and the organ part being an  
organ, at least in my head.

> If so, here's a bonus question: what do you call an instrument  
> where each note has its own dedicated tone generator - other than a  
> pain to build and even more of a one to get in tune ;-)

Aaah..yeah.. I've seen one of those too..I think it was called a  
"piano" or something...;)

T.