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Copyright 2009 Dale Clark
I’d like to start my discussion of reed dimensions by comparing the length and wire placements of my style A reeds with style B. Style A reed measures 54 mm (millimeters) overall: first wire at 25 mm from butt of reed, second wire at 16 mm and third wire at 5 mm. Length from first wire to the tip, also known as the bahn, is 29mm. Style B reed measures 57 mm overall: first wire at 27 mm from butt of reed, second wire at 18 mm and third wire at 5 mm. Length from first wire to the tip is 30 mm. How can both reeds be made to play in tune on the same bassoon and bocal? First, the profile of the blade is thicker on the style B. For every mm in length longer the reed is, I make the blade .05 mm thicker, especially at the back by the shoulder or ledge where the bark ends. On the B style the collar also tends to have a more gradual fall off into the blade as opposed to the abrupt ledge of the A style. The thicker cane provides more resistance, there by raising the pitch a little to counter the resistance lost in the extra length of the reed. Finally, the difference in embouchure pressure made by individual players can result in the need for slightly different reeds.
I grew up around house construction and built my own house, labor and all, in my late twenties. So, I like to use analogies from carpentry and house framing when discussing the length and strength of the blade of bassoon reeds. A floor joist, the wooden member that supports a floor, is weaker in longer lengths if the width of the board remains the same. So, I learned that you needed a 2 x 12 inch board (2 inches thick by 12 inches wide) for a 16 foot span while a 2 x 8 inch board would work for a 12 foot span. While the 8 inch wide board might not break at the longer span, the floor would be weaker and would tend to vibrate or sag. These joists, for the greatest strength, are placed with the width vertically under the floor. If laid flat, the board would be much weaker as a load bearing member. The blade of a bassoon reed, with the tip closed, looks much like two wide boards placed together laying flat. When released the tip pops open because of the resilience in the blades. Resilience is the tendency or ability of a material to keep or return to its original form. A reed blade of 30 mm in length is weaker than one of 29 mm in length if the same thickness of profile was used for both blades. The 30 mm blade would even be thinner at the last mm because the profile tapers at the tip. So, the thinner, longer blade, because of its weakness, not just its length, tends to play flatter unless the profile for the longer reed is made thicker.
Another factor in the performance of the longer reed, the style B, is the increased width at the tip. The style B is 15 mm wide and the style A slightly wider than 14 mm. Even though both reeds are from the same Fox #2 shape the style B is wider at the tip because, if the overall reed length is longer, the shape flares wider from the butt towards the tip of the reed. A wider tip, at this length, is more difficult for me to control and play in tune in the upper register and may even cause the reed to be flatter overall. Even with my reeds of the same length and profile but with different shapes, such as the style A and style D, the wider style D, made with the Rieger 1A shape, is not quite as easy to play in the very top register but is great in the mid to low registers. These performance tendencies can of course be mitigated with the finish scrapings and adjustment of the wires but may help players determine which reed best fits their needs.
The last factor I will discuss has to do with the strength of the blade in general. As with a board laid flat, the reed blade is stronger and more resistant from pressure to the sides than the top and bottom. Thus the properly profiled blade is able to close freely as the air passing through forms a vacuum and then pop back open because of its strength and resilience. Also, the natural curvature of the cane helps the blade return to its open or arched position. This arch can be strengthened not only by the thickness of the cane but by the shape of the reed’s throat and tube controlled by the wires. Dr. Matthew Ruggiero, IDRS honorary member, taught me that the first wire controls the tip opening and the second wire the shape of the throat. Of course the second wire can cause the tip to open and close but to a lesser degree than the first and the squeezing operation is opposite to the first wire because of the fulcrum. I’ll discuss the wires operation more in another blog. What I want to point out is that because of the strength of a board, or in this case the reed blade, from the sides, squeezing the first wire from the sides is not always the technique I use to open the reed or create more arch. I also use a pin or throat mandrel to open the tip if the first wire is already what I consider to be round enough. Some forming mandrels are not long enough to open the tip the correct amount when forming the reed so the reed may seem too weak and need the arch increased by using a longer mandrel made for this purpose. I was fortunate to have Gary Echols, retired Professor of Bassoon at the University of Nebraska-Lincoln, give me some of Lou Skinner’s pin mandrels. I am very grateful for all the equipment Gary gave me when he retired that helped provide the motivation to start Clark Bassoon Reeds.