Harmonizing A Scale

Utube Harmonizing A Scale

C Dm Em F G Am Bdim C

C is I then Cmajor scale
C is IV chord C is fourth of G Cmajor scale use Cmajor or G lydian
C is V chord is fifth of F Cmajor F myxolydian

Cmajor Dmajor chords implies a G major scale
solo using Cmajor over using C
solo using Dmajor over using D

OR G implies Lydian to Myxolydian