I can't sing at all but watched a bunch of Jeannie Deva's ArtistWorks videos - because I wish I could. She also has a website, you can Youtube her etc. She has/had (passed away) an impressive CV. Anyhow, fascinating stuff. One of the takeaways was that if you are not a natural singer, and maybe feel you can't sing, it's because you don't know how. Her going through the "how" was, to me, kind of amazing.