Originally Posted by: BammBamm22Hello i am working on some of the lessons that involve adding Major 3rds and minor 3rds to perfect 5ths to get different chord scales with all the differerent keys. the C major scale is very simle becuse there is no flats or sharps, but when i try to go to a differerent scale/key i get confused when it comes to adding the dominant 7. i have watched all the videos on scales and triads and adding 3rds but im still lost. the question i have for you is i heard they call this 7 note a flat 7th. So if i take the scale chords in the key of D, the primary chords I IV V would be D-F#-A. i then take the V chord which is the A. The part that i get lost in is... do i continue to use the notes in the key of D to get my V7th, or since the V chord is an A, do i now use the the key of A (A major scale) to get my flat 7th. in the key of A the 7th is a G# and when i flaten it it now becomes a G. is that correct or is there a simpler way. thanks BBg

The I, IV and V(7) chords are D, G and A(7). You may use A or A7 because both are considered to be "dominant" chords.

The "7th" note added to the A Major is the note "G". This means you stay in the key of D while the V(7) chord is being played.

The way you arrive at the "7th" note that is added to the V chord is by going up in the A Major scale to the 7th step and flattening it from G# to G like you said. This gives the chord (V7) the "dominant" function...the flat 7th.

Hope this helps