Let's just have a look at "The Fear", if any, of singing, and consider the idea of putting it on the ground.

Then The Natural Minor (Aeolian Mode) 1; 2; flat 3; 4; 5; flat 6; flat 7; 8.

And then have a look at the vocal round in "People Want to Sing", by Brisbane Band 'Kooii'. And Try some exercises with Vibrato.

Links:

https://kooii.bandcamp.com/track/people-want-to-sing 2012

(With Thanks to Peter Hunt and Kooii)