Lick Interchangeability
A student asked this question this morning: "Can most bluesy licks be used over any of the three chords but are there some licks that are just more suitable for the IV chord?"
The answer I feel is worth sharing...
"Yes, you are correct, most bluesy licks can be used over any of the three chords, and there are some licks that are more suitable for the IV7 Chord, and especially the V7 Chord.
As you continue your studies I'll show you when it doesn't work... like when a note is held for a long time in an A Lick that contains a note that will clash over other chords. 3 draw for example, which is B, will sound nasty against the Bb of the IV7 Chord.
In your chord studies in Music Theory 3 you'll learn that if you hold a note, it should be a note of the chord you're playing, unless you're using that note to build tension (which will yearn to be resolved, thus creating harmonic movement). All music is based on tension, and the release of that tension. A non-chord tone provides a lot of tension, which can be good, especially in blues, but you'll need to resolve it to a chord tone to release that tension. How much tension you use is up to you, it will be part of your style, but be cautious to use too much tension, too often, you don't want your listener to get musical-constipation.
You're also learning this in the Accompaniment Lessons, via the exercise "Hole Changes," which teaches you which notes sound good when on a given hole of the harmonica at a specific location within the form. So, for now in your improvising studies you'll use the rule that "phrasing trumps chord change," and later we'll be more discerning regarding the qualities a lick has to match, or not match, over our three chord of the blues.
P.S., you're right not to include the V7 Chord, that's a special area within the 12 Bar Blues (where V-IV-I Licks live)... V7 Chord licks will not generally work as A Licks. Since the IV7 Chord has a common tone with the I7 Chord (the Root of the I7 Chord, G, is the 5th of the IV7 Chord), IV7 Chord licks, when focusing on that G, generally work on the I7 Chord, but don't use this is a hard rule."
