A book called Caruso’s Method of Voice Production: The Scientific Culture of the Voice, offers an interesting approach to singing, inspired by the famous Italian opera singer, Erico Caruso.
The foundation of the vocalizing approach–in this book written in around the 1920’s–is that singing should be easy and natural and more significantly, that the singing voice is the same as and an extension of the speaking voice. Singing is just talking with melody added.
The following is a quote from Richard Wagner, who is widely considered to have transformed the art of the opera with his work.
…the vanishing of that peculiar cramp which drives our singers to the so-called head-note, that terror of our singing masters, which they attack in Vain with every kind of mechanical weapon, although the enemy is but a simple bent to affectation, which takes the singer past resistance when once he thinks he has no longer to speak, but to ‘sing,’ which means in his belief that he must do it ‘finely,’ that is, make an exhibition of himself.
It sounds cerebral, but in the end they’re just saying to stop trying to be a singer and just tell the damn story.