Duo-Art Expression Coding
By Craig Brougher
The question was in regard to the Theme being set to one "degree" above the Accompaniment. Jim Heyworth's answer was correct, but I would like to add this. For example, the zero intensities of both Theme and Accompaniment are different. The Theme setting is between 1/4"- 1/2" vac. above the Accom. setting. The reason for this is so that the Theme can always override or take precedence *over the same intensity setting* on the Accom. side. It's spring is larger, anyway, and its slope is greater, so it builds up faster. A degree just means "some." Actually, it is the loudness that is just the next step up the decibel scale that you are able to detect, i.e. 3db.
If the score calls for a #10 Accom and a #10 Theme, then as soon as the snakebite hole appears, that Theme will override the Accom. loudness. But if the Theme called for is a #10, and tries to play over a slightly louder accompaniment setting the one-way theme flap valves in the box will not open because the Accompaniment is still greater than the desired accent, and keeps them snapped shut. They protect that side of the stack from receiving a softer accent than what they are already playing. (Which is what Jim Heyworth also said). To suddenly drop the pressure with a Theme intensity requires that you drop out the accompaniment first, which in turn would depressurize the entire stack, not just treble or bass. (The Accompaniment perfs are the 4 holes on the left end of the trackerbar.) This is why Theme accents are always louder, and never softer than accompaniment played at the same time.
A full Duo-Art is sort-of like a Recordo with accents. Like Jim said, it plays mainly on the accompaniment settings, and then accents certain notes and passages by precision snakebite holes which allow a few milliseconds' time to set up the expression before playing it.
So Accompaniment changes require more time to express than Theme changes because of the time required by its accordions to get adjusted. Accompaniment is limited by the speed with which the accordions can move. However, Duo-Arts also play notes between Accompaniment changes, which must mean that Aeolian timed their speed and knew about how much power they could expect at a certain degree of collapse or relaxation. This also might explain why certain unrelated codes were used in transitions that didn't seem to affect the notes.
Craig B.
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(Message sent Sat 26 Oct 1996, 17:42:06 GMT, from time zone GMT.) |
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