Originally Posted By: Matt Finley
Jim, what we’ve been discussing is that a key signature of no flats and no sharps could be the key of C Major, or its relative minor, A minor. In that example, both scales would be all white keys on the piano.

That’s the simplest explanation I can think of. It’s why I mentioned above the odds are 50%. For any major key, like F, there is a relative minor using the same key signature, in this case Dm (both with one flat).


Matt, your explanation makes sense, thank you.

I didn't realize both C major and A minor have no flats. I've read some people advise looking at the last chord in a song as the last chord can help you determine the song's key. The rule of thumb is nice to know because major keys and relative minor keys share key signatures, correct?

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