posted on Aug, 22 2014 @ 10:29 PM
I don't exactly understand the problem (unfortunately I can't make your links work for me). You have a melody, don't you? A solo is a melody. And a
melody automatically gives you a set of chords, based on the root note of the melody. You should be able to hear them in your head automatically. If
you can't, you may be trying to run before you can walk; in which case, you need to understand better how chords work to support a melody. You can
learn that theoretically, but you will never really get it until you understand it 'by ear'.
A musician who plays by ear should be able to hear a melody and create an accompaniment for it without too much trouble. If the song is fairly simple,
you can do it on the fly. The chords needn't be elaborate — simple major, minor and 7th chords are more than enough.
The way you use dominant sevenths is like this. The 'blues scale' is actually a simplified minor scale played over major chords, but with only one
difference: the last note in the blues scale is flattened a semitone from the last note in a 'normal' minor scale. A dominant chord is a chord
containing that flattened blues note, so you use it in places where you want to emphasize that 'blues sound'.
You can write a blues song that's all dominant chords and it will sound fine, but the places you'll normally find them in a blues progression are in
the turnaround at the end of the verse, and sometimes in the second bar. The latter are usually found in slow blues, or blues that have more than
sixteen bars, when you sometimes go to the IV chord in the second bar before returning to the I chord. The IV chord you play there is usually a
dominant chord — a seventh, a ninth, an eleventh or some such.