I am a 73 year old vocalist that now has a voice that is shaky Is there anyway to correct this?
If the shakiness is a vocal issue and not due to some other physical development then yes, I believe it can be improved. You will need to get a very refined phonation, good forward resonance, and think of using a straight tone (no vibrato). Once the voice is pure and clear it will start to spin on its own. All of this will need to be supported by some strong, steady expansion in the lower ribs to keep the air away from the voice. That is, use as little air as possible to make the tone.