Explain to me what a dominant function is?
I'll try. Dominant chords or 7th chords only appear in all natural major scales only once. As a V7. It is the only position where the tritone appears naturally and sounds natural. I say again, Dominant 7th chords only appear once in every key. That makes them unique. (Lets make half and full diminished another email or discussion. Though the same idea prevails with some strangeness.) Dominant chords are given this name, because normally or in a traditional sense, they'll naturally resolve down a 5th to I or to a period of rest. Also called a pentultimate. Makes the progression move. At the moment, I haven't altered anything. A human penchant (to alter or change). Without the dominant chord, music is naturally stagnant (a largely supported POV, or we'd still be listening to Gregorian Chants). Thus, the dominant function. Thus, the tritone. Hope this helps. Answer the next question in an another post.