Elmo89m said:
i know you meant well but...i am not looking for a magic formula i just want to know where in the great big book of guitar theory, finding the key is located. I can work things out with my ears but i would rather be able to say, hey this is my chord change blahblahblah...that second chord i play is my root and its an A. OK...lets play the minor pentatonic starting at the fifth fret...hey that sounds good.
tell you what. I think we'd be able to give you some more information if we had more to work with. Answer these questions if you could:
1) are you the songwriter?
2) are you the singer, or do you sing at all?
3) what are the chord progressions to 3 of your songs?
We won't necessarily be able to tell what key they're in just by that without hearing the vocal melody, but we could make some educated guesses.
The problem with the "three major chord" way of determining keys is that it's probably about as accurate as the "first or last chord" in the song method. There are many, many songs that have three major chords in them, but the key is not what you'd think it should be.
Take "Sweet Home Alabama" for instance. The chords are D, C, and G. By three chord method, this song should be in the key of G, but D is actually the tonal center. The chord progression is not V, IV, I in G. It's I, bVII, IV in D. And there are many more examples like this.
The song "Werewolves in London," contains the exact same chord progression. It IS, however, in the key of G. One of the factors that determines these songs key center is the vocal melody. "Alabama" consistently resolves to the D note (and that note feels like home), while "Werewolves" resolves to the G note (and that note feels like home).
The most accurate method of determining the key center is to use your ear. Hum notes until you find the note that sounds like the final resting place. Some people say, "find the last chord in a progression" and that's usually the I chord (or some say the first chord). But as others have pointed out, that's not nearly common enough to rely on it. However, the final note in the melody is often the tonic-- much more often than the chord being the tonic.
Think of the "Love Me Tender" melody (as mentioned in an earlier post).
"Oh my darling, I love you, and I always will."
"Will" is the tonic note of the song.
Keeping in the Elvis mode:
"Let's rock, everybody let's rock.
Everybody in the whole cell block was dancing to the jailhouse rock."
"rock" is the tonic.
Let's use a Beatles song:
(chorus) "I wanna hold your haaaaand
I wanna hold your hand."
"hand" is the tonic.
or "Come together ... right now ... over me"
"me" is the tonic.
Now these are all very clear cut examples, and there are still plenty of songs that aren't this clear. Take "Smells Like Teen Spirit" for example.
"Load up on guns and bring your friends, it's fun to lose and to pretend
She's overbored and self-assured, oh no I know a dirty word."
This song is in the key of F minor. However, Kurt's beautiful melody doesn't make that obvious. The phrase ends each time on the note G. My point is, though, that this note (G) definitely does NOT sound like "home." That's part of the appeal of the melody---it's unresolved or "hanging" sound. After this part, he goes into the "hello, hello, hello, hello, how low" bit which alternates between the Ab and G notes. Only on the word "low" does the melody reach the tonic. Sing the "hello" bit over and over. You can tell that it's not resolved. But when the "how low" comes, the phrase feels resolved or finished. Does this make sense?
Again, answer the above questions if you could, so we can get a better understanding of your situation.