I started studying music theory on my own but could use someone to confirm if i'm correct
I'm assuming that the progression D - Cadd9 - G is in the key of D major.
The D major scale contains the notes: D, E, F♯, G, A, B, and C♯
But when i'm playing over the D major scale on my guitar, the C# note never seems to sounds right.
I know that Cadd9 contains these notes: C - E - G - D (there's no C# in there)
The G major chord also does not have a C#: G - B - D
And the D major chord neither: D - F# - A
So if i understand correctly, It is not because a note is in the major scale of a certain key that it always can be played, it depends on the chord played at that moment right? For example, will a G note sound right over the D chord of the progression?