We all know that being “relaxed” when we sing is good. But what, exactly, is relaxed?
Relaxed to a jazz singer is certainly not the same as relaxed to a classical singer. Relaxed is very relative.
Generally, “poised” is a better term, because poised means ready for action is a comfortable and alert manner. The muscles involved in singing need to be poised. Comfortably flexible or adjustable would be another way to define what has to happen.
It is frequently the case that students, in striving to “relax” end up making the muscles of the throat, tongue and mouth deadened and immovable. They certainly are relaxed, but like a pool of melted wax, they can’t do anything but lie there.
In a healthy professional singer, the muscles that impact the sound must be both flexible and strong. If they are instead flaccid it can actually cause problems that would not otherwise be there. The bouyancy is missing and the muscle “tonicity” that comes from having the muscles be able to easily contract and stretch is eliminated. This is the issue with the people who hold strongly to the idea that the larynx should never move out of a lowered position. It makes for a big, dark, and full tone, but high notes, well, they can’t come from a larynx that is stuck at the bottom end of a throat, no matter what else is done. All those folks have trouble singing up high. The throat closes and contracts, the tongue cannot release in the back and the vibrato gets slow and wide. In any style.
Flexibility exercises that include light, soft and rapid scales and arpeggios, with changing vowels, using a wide pitch range, done at moderate volumes are useful to anyone stuck in a lugubrious tone. Tongue exercises, especially from back to front are also helpful, as are face/mouth changes.
To those who teach and those who sing, do not “over-relax”. Keep your sound alive, comfortable, moveable and responsive. Even at loud volumes where there is great stability, things should still feel “OK”. If not, it might not be that you are “tight”, it might be that the muscles involved are doing too little. Wake them up and it will become easier to do what you need while remaining “relaxed enough” to get the job done well.