Also see Diaphragm Breathing
Good breathing and breath control when playing the saxophone is important for two reasons:
The second of these is probably the most important as it can actually help your tone. It is a well established technique to keep your throat open while playing (an open throat is what happens when you yawn, as opposed to a closed throat which happens when you cough). This is important for singers as well as wind players as a large part of what shapes the sound is the physical dimensions of the inside of your mouth, throat and possibly lungs and nasal cavities. But being able to control the pressure of air in your lungs, while keeping your throat open, is not something people do naturally. Normally the air just rushes out unless you close your throat to stop that happening. The trick is to use a muscle underneath your lungs to control that natural tendency for the lungs to contract and expel the air all at once. This is the diaphragm.
A good question, especially as it is a muscle most people are not even aware of, let alone know how to control. Instead of trying to, it’s much easier and more effective to visualise it as your abdomen. It isn’t, but it does seem to be connected and this is the best way I have found to communicate diaphragm control:
Imagine the way you would tense your muscles when somebody is about to punch you in the stomach and aim towards this kind of control as you push your abdomen out while breathing in. This is not something you can learn overnight, especially after a lifetime of shallow breathing into the top of the lungs (which is how most people breathe). Diaphragm breathing forces you to use the lower part of the lungs as well as the upper part so gives you a much bigger lung capacity and control. A great way to practise it is to try yoga breathing.
I have also outlined below 3 daily breathing exercises which were practised by the great saxophonist Sonny Rollins. These will help expand your lungs and your diaphragm control. I have noticed that these exercises will also build up the muscles around the chest and shoulder blades.
This is easiest to do lying down on your back, but can also be done standing or sitting with your back straight. It consists of three phases in and three phases out, each phase should flow gradually from one to the next
Hold this for a second or two without closing your throat, it should be your diaphragm, abdomen and rib muscles gently tensed that stop the air rushing out. Next breathe out in the same order, abdomen, chest and shoulders and hold for a second or two without closing your throat. Of course, you are not actually breathing into your abdomen, but it can be useful to think that as your abdomen muscles expand outwards, air is flowing into it. In fact the lower part of your lungs is expanding downwards to fill the place left when your abdomen moves forwards.
Each of these will help develop and expand a different part of your lungs and ribcage.
Start this standing up with a straight back, arms by your side
You can combine this with the yoga breathing exercise, expanding the abdomen, chest and shoulders in that order.
Start this standing up with a straight back, arms straight out in front of you
Concentrate on phase two of the yoga exercise, i.e. chest expansion.
Start this standing up with a straight back, arms by your side
In this last exercise, be aware of your ribcage expanding sideways, and phase three of the yoga breathing: the top of your lungs.
As with any exercise regime, it is bad to rush in and overdo things. Try starting with 10 of each exercise once or twice a day and gradually build up.