Before I book in here is what I want to achieve:

I`m 74, male, have sung all my life in choirs, at parties with my guitar etc.

I hit pitches correctly, but....

- my voice is not really clean. It always sounds a bit around the correct pitch irregularly. If my choir-neihbour sings it sounds like a trumpet. He must have has singing education. I always sound ...disappointig. So I want my voice to sound strong and clear/steady

- when I awake in the morning I can sing three octaves. From low B to high B including falsetto for the last half otave. Switching between normal and falsetto works without cracks when I sing a sirene.

Half day later I cannot sing falsetto anymore and my lowest tone has dropped to E. I want to have my voice trained for full range at any time of the day.

Are the trainig courses that help me to achieve those goals?

Hi, Karsten! Yes, I do believe that our beginner courses will help you achieve more consistency in your voice. 

You may also enjoy this lesson on resonance - I thought of it when you mentioned your neighbor's clear "trumpet-like" voice!