I'm not a good singer but I can sing in good tune and within my voice range. When I was studying in high school. I auditioned for a glee club. And my voice was classified as bass.
Every Friday right after the dismissal of our last period class we gathered in the school music room and practiced vocalization under our voice sounds good. It's easy for me to adjust my voice to the tune of the part of music where I used to sing for I have an ear of music.
Again when I reached college, I also became member of the college glee club. This time I sang tenor or bass voice part. It takes to practice to sing well and to feel comfortable with your voice range