Keyboard instruments

2002-06-24 09:29 pm

on the organ and some harpsichords why are there multiple manuals

Re: Keyboard instruments

Reply #1 – 2002-06-25 02:45 am

And while we're on organs, would anyone be kind enough to explain stops to me? It's my impression that they've got to do with tone. Yes, no? Any light anyone can shed on this would be appreciated.

-m

PS. Did you hear about the recent merger of Xerox with Hammond? They're going to start making reproductive organs.

Re: Keyboard instruments

Reply #2 – 2002-06-27 03:25 pm

Reproductive organs. Yakity har.

Search "Harpsichord" for a little essay I wrote about writing for the harpsichord.

The short answer is that it's possible to have a different sound on each "manual" (as the keyboards are called in this case), and either switch quickly from one sound to another or play with each hand on a different manual. On the organ you also have a keyboard to play with your feet (the "pedal"). So it's possible to have the effect of three different instruments on the organ, one for the feet and one played by each hand.

In a really simple pipe organ, you might have two 45-note manuals and a 30-note pedal. Every "stop" is a set of 45 (or 30) pipes set up for a particular sound, and sometimes an octave higher or lower than normal. You "draw" the stop by pulling a knob and that engages that stop on the keyboard it's controlled from. Some pipes are like big recorders, some have reeds like a bagpipe chanter, some are wood, some are metal; they all sound different. So if you have say three stops on each division of your organ, that's 360 pipes. And nine stops is a very small pipe organ; the big ones have thousands of pipes and that's why they cost so much. The low C requires a pipe 8 feet long, so a stop at regular pitch is called an "8 foot" stop. One an octave higher is a "4 foot stop". You have your 2 foot stops an octave higher again, and your 16- foot stop an octave lower, even 32-foot or 64-foot stops on the biggest and most pretentious organs.

Some electonic organs, like the Hammond B-3, use the multiple keyboard set-up so you can play in the pipe organ style, with contrasting sounds. I've never understood why there aren't more two-keyboard synthesizers. (Short answer: most synth players come from the piano, not the organ). Most have divided keyboards, but that's not as flexible. Some guys use two controllers stacked on top of each other but plugged into the same synth unit.

The harpsichord borrows a lot of terminology from the organ. A standard large harpsichord has three sets of strings (they call them "stops" or "registers"), one an octave higher than the other two (which is called a "4-foot stop" by analogy with the organ), and two manuals. Sometimes they play the melody on one manual and the accompaniment with their left hand on the other, or have slightly contrasting sounds for something in two equal voices, one in each hand.