Hey all,
Lately ive been studying up on chords, how to construct them, and how to put them into music, and i was wondering: When using other chords that arent just plain Major or Minor, such as Add chords, can you put them anywhere in the progression that is fitting? Such as replacing the C major chord in a C major progression with Cmaj add9 chord? Thanks!
Schecter Blackjack
Mesa F-30
Line 6 Verbzilla
Bad Monkey
FAB Chorus
If the extension fits in the scale then go for it.

Even if it does not fit in the scale, play it if it sounds good.

And you would write it as Cadd9. Unless otherwise noted, the chord is implied as major.