When playing the guitar, how do I know which scale to play over a chord progression? For example, if I play a G, D, Em, C chord progression, which scale would I play and why?

Answer 1

Inherently the chord progression implies Major. If I were soloing over that chord progression, you can use the F# note but I would use it as a passing note or definetely not hang on that F# note too long.

Many famous rock/pop songs use this chord progression like:

Bocelli - Time To Say Goodbye

U2 - With or Without You

James Blunt - You're Beautiful

Maroon 5 - She Will Be Loved

Journey - Don't Stop Believin'

Denver - Take Me Home Country Road

Jovi - It's My Life

Marley - No Woman No Cry

Beatles - Let It Be

a-Ha - Take On Me

In general though, I would play a blues scale over the root of the song. Perhaps you can also use a mode, I guess it depends on the vibe of the song. Always experiment on your solos. I normally focus on the "melody" or motif that I hear and compose something.

Trust your instincts, the style you want to express, use your ears and incorporate variations.

Answer 2

Based on the assumption that you want the answer to this question so that you can create your own melodies over this progression, you should know there are two (ideally interlocking) approaches:

1. "Horizontal" = play the same scale over the entire set of changes (G major or, commonly in many styles, G major pentatonic both work fine over the OP's chord sequence)
2. "Vertical" = specifically targeting components of the current underlying chord

Horizontally you can intuitively noodle up and down on one or both of the abovementioned G scales, feeling your way around to land on butter notes.

Vertically, however, you navigate the changes concentrating on chord tones. Note that (most commonly) the new melody note on beat one of the new measure is one of the components of the new chord that is approached step-wise directly (from above OR below) from either a component of the old chord on beat four, or a passing tone moving from a component of the old chord to a component of the new chord on beat one of that bar.

As can be seen, the vertical is a more cereberal approach and requires total familiarity with the underlying chord sequence as well as each indivdual chord's compenents and how they are situated according to the relationship between the preceding and succeeding chords (and their respective chord tones).

Vertical is much more cerebral and challenging approach than the intuitive horizontal scaly way is.

The scalar approach to creating melodies works of course, but ultimately the vertical approach is more interesting to both the player and the listener.

Answer 3

If you consider the C chord to be the IV of the sequence, then Em is the vi, and D is the V. Taking that into consideration, you would play MOSTLY a G scale. G Major has all of these chords. However, I agree with the other teacher. The C scale has no F#. While that chord is playing, emphasize the C, E and G notes, maybe even skipping over the F# during that time.

I'm also mystified as to why the sequence ends on C. Is there an implied G at the ending, or is this a plagal cadence - unresolved? If the C chord is played with a G in the bottom, that would make sense - followed by a G chord.

You would stick mostly with a G scale.

Answer 4

The G, Em, and C chords are all in the key of C.

Yet the D chord needs a F#, that is not in the key of C.

No major or minor scale fits the chord progression.