Mouth Aperture
As previously explained your reed can either close up or open up as a result of changes in ambient heat and humidity. If it has opened up and the mouth is too large your chanter pressure will be too ‘heavy’ to play comfortably, the tone may be too harsh, the tuning may be poor, the low ‘A’ especially might be too flat and the hard ‘D’ difficult to achieve and sustain. Pitch may be too flat overall. Vibrato may be very unpleasant, especially on back ‘D’. In the case of any of the above symptoms close the mouth until the reed is performing properly. If the mouth has closed up and is too narrow, the reed will take very little pressure to play and may actually close up completely as you try and play. It will sound very weak and give a puny tone. It will be out of balance with your drones and close up at the pressure needed for your drones to sound. Hard ‘D’ will be very difficult to achieve. Pitch will probably be too high. In the case of any of the above symptoms open up the mouth until the reed is performing properly. You should be aware that very slight adjustments to mouth aperture will have a marked effect. Experience will eventually inform you of correct adjustments. There are no hard and fast rules about ‘correct’ mouth aperture and this may vary from maker to maker, the aperture is ‘correct’ when the chanter is performing well for you. My reeds are normally no more than 0.5mm at the centre of the mouth when they are in correct playing adjustment.
Using the Bridle to open or close the mouth aperture
Keeping the mouth in correct adjustment is the one thing you will probably need to do more than anything and the copper Bridle is there to control adjustment of the reed mouth. I use two wraps of wire whereas the more common Bridle is made up of a single wide strip, or ‘collar’, of copper of anything from 3 – 5mm in width. Collar or wire Bridle it really does not matter as long as it performs its intended function, and its sole purpose is to control the mouth aperture. I personally find the wire Bridle easier and less risky to attach and manipulate and so this is my preference. Always exercise extreme caution when making any kind of adjustments to your reed, splitting the reed is easy and very costly.
Opening the Mouth
There are two ways of opening the mouth: Gently squeeze both ‘corners’ of the Bridle between thumb and forefinger in a pinching action towards each other once or twice. Looking at the mouth as you do this you will notice the blades flexing apart, you might not notice that there has been any change but the change may be extremely slight and imperceptible, and a slight change can make all of the difference. Having performed this action once or twice return the chanter with reed to the windway and test. You must do this repeatedly until you have achieved the desired result. The second way of opening the mouth is by using your thumb nail on the ‘corner’ of the Bridle to carefully push the bridle upwards towards the mouth, usually a movement of no more than 1mm or less is necessary. You can actually make a very slight adjustment by simply moving only one side of the bridle up by 0.5 – 1mm. If this is not enough then push the other side up by the same degree Using the guidelines from these notes you should be able to keep your chanter playing in tune with itself, producing a good tone and playing at a comfortable pressure.
Closing the Mouth
There are two ways of closing the mouth: Gently squeeze the ‘flats’ of the Bridle between thumb and forefinger once or twice. Looking at the mouth you might not notice that there has been any change but the change may be extremely slight and imperceptible, and a slight change can make all of the difference. The only efficient way to find out if this has helped is to return the chanter with reed to the windway and try playing. You must do this repeatedly until you have achieved the desired result. The second way of closing the mouth is by using your thumb nail on the ‘corner’ of the Bridle to carefully push the bridle down towards the thread, usually a movement of no more than 1mm or less is necessary. You can actually make a very slight adjustment by simply moving only one side of the bridle down by 0.5 – 1mm. If this is not enough then push the other side down by the same degree.