If you were playing a simple three chord song, like a lot of bluegrass songs, a simple I IV V for easiness I guess. And you wanted to find the melody of the song…do you use the scale of the key for the whole song, or would use each chord changes respective scale? Example key G. So one is G four is C and five is D. Would you use just the G scale to locate the melody notes (G A B C D E F# G) or the scale for G when in the G chord like listed, the scale of C (C D E F G A B C) for when on the C chord and the scale of D (D E F# G A B C# D) when on the D chord?
Looking toward using the fiddle some day at our jam where I usually play banjo and have never understood this and really need to start mastering how to find the melody versus a generic placeholder solo (as Pete Wernick) calls a solo of just banjo rolls over the chords.
Thanks in advance for any help.