Posted by Brian Frederiksen on April 07, 2002 at 12:39:13:
In Reply to: low register articulation posted by steve on April 06, 2002 at 16:56:52:
A few weeks back we were printing copies of Mickey Wrobleski's Low Register studies and there was a blanl page at the beginning. We decided to print a portion of an interview with Mr Jacobs.
The relationship between air flow and air pressure is the key of playing in the low register of the tuba. Arnold Jacobs explains from ARNOLD JACOBS: SONG AND WIND:
In 1959 or 1960, four members of the Chicago Symphony, with instruments, traveled to the University of Chicago for tests. They were Adolph Herseth, trumpet; Philip Farkas, horn; Robert Lambert, trombone; and Jacobs, tuba.
Jacobs spoke to Bill Russo on Chicago radio station WFMT-FM about these tests:
Russo, (BR) - What's the difference between [brass] instruments?
Jacobs, (AJ) - “The trumpet would use the least amount of breath, but under the greatest amount of pressure of any of the brass instruments. The tuba would be just the reverse. It would use the most in terms of volume of air and flow, but under the least pressure. We found that the flow rates in very high range playing would be very low—say maybe ten-liter-per-minute flow rate under a pressure of sometimes in excess of a pound-and-a-half to two pounds. In his lower range, he might be playing with a flow rate of maybe twenty-five to thirty-liters-per-minute under a pressure of maybe eight or ten ounces.
“On the tuba, my intra oral pressure—the pressure as measured in the mouth cavity while playing—we inserted a little tube into the mouth while playing, and the pressure was read—goes as low as two ounces in general playing, but at the same time, my flow rates may go anywhere from seven-liters-per-minute playing as softly as I can, to well in excess of 120 liters-per-minute playing in full volume.
“Dr. Benjamin Burrows who helped me with these experiments was rather intrigued with the fact that you could draw one curve for the entire brass family in terms of how much air is used, and how much pressure is used in producing this flow rate on the instruments.
“Wherever we played notes that were enharmonic, even though they were on different instruments—our work efforts and flow rates were practically identical. As an example, when I played a high C at a given dynamic that we were working to, I was using about six ounces of intra oral pressure and about ten liters flow rate per minute, and in graphing this we found that Mr. Herseth, on exactly the same note, was using practically identical pressure and flow.
“On a different note, with Mr. Farkas, again we found that my pressure and his were about the same. Flow was about the same—even though we were using different instruments. Our embouchures in coming to a given size and shape had a certain requirement for the breath in terms of pressure and movement.”
BR - “The flow rate increases for lower notes on a given instrument?”
AJ - “In the brass family, yes. At a given dynamic level, the flow rate is almost invariably greater in the low range compared to the high range.”
BR - “And the pressure decreases for the lower notes?”
AJ - “Exactly.”
BR - “But now, when you say that different instruments have the same flow rate and same pressure for a given same note . . .”
AJ - “Enharmonic, yes.”
BR - “Say for middle C, does that mean then that as the tuba increases its flow rate to ten, the trumpet decreases its flow rate down to ten?”
AJ - “Exactly. As the trumpet goes into his low range, the pressure eases off and his flow increases—as I go into my high range on the tuba, my pressure increases and the flow decreases.”
BR - “Terrific. What are the implications of this? There must be millions.”
AJ - “Well, there are many implications, as you say, one is psychological to those of us who play the tuba. We must realize that we do not have to work very hard when we play in the high range. I have many students who will go into severe isometric contraction simulating the work effort of the trumpet when he is working in his high range, when actually it is not needed.”
*Arnold Jacobs: Song and Wind. Copyright ©1996 by Brian Frederiksen. Printed in the United States of America. All rights reserved. No part of this book may be reproduced in any form or by any electronic or mechanical means without permission in writing from the author.