How to know singing is in a particular key

Question

At Deering's web site, they have a blog entry Learning Banjo by Ear for Beginners. The third step says, "Sing that melody aloud in the key of G. (keep strumming that chord if you need a reference point)."

So, there are beginners, and those of us who are REALLY beginners. :)

If I'm singing a song and strumming a G chord, how will I know I'm singing in the key of G, versus another key, or none at all? Is it possible to be in a wrong key where it still sounds okay, or will there necessarily be disharmony?

Answer 1

The key is the part which says "keep strumming that chord if you need a reference point".

Keep strumming the G chord and sing "Mary had a little lamb" over and over again. It may help to stick to a single strum of the chord each time, right on the "Ma" part.

Keep changing the pitch of your voice until it fits with the G chord you are strumming.

When you're singing it in the key of G, you'll know.

Keep at it! :)

Answer 2

Is it possible to be in a wrong key where it still sounds okay, or will there necessarily be disharmony?

It depends.

"Mary Had a Little Lamb" only uses four different notes in the entire song; represented in scale degrees, they are, in order:

3-2-1-2-3-3-3-2-2-2-3-5-5-3-2-1-2-3-3-3-3-2-2-3-2-1.

The degrees used are 1, 2, 3, and 5, which, in the key of G, are G, A, B, and D, respectively. The major scales that use those notes are C (where they would be 5, 6, 7, and 2), G, D (where they would be 4, 5, 6, and 1), and A (where they would be 7, 1, 2, and 4). Therefore, theoretically, you could sing those notes to that tune in four different keys and not have any of the individual notes "clash". This is not necessarily the same thing as them "sounding good". Additionally, given the right context, you could sing those notes in other keys where they would "clash", and they'd still sound "good".