I don't think it's a matter of being dumb or smart. There are different approaches with different trade-offs in terms of where they shift the complexity. You can find musicians/students who had great success or no success at all in all approaches. Sometimes people can be closed minded to approaches that put the initial complexity in areas that are outside of their comfort zones. Obviously one doesn't have to conquer every area outside of their comfort zones if they found something that works for them.
Some approaches may have a superficial facade of simplicity but students can still get stuck in the disguised barriers of the hidden complexities for decades without making meaningful progress. Other approaches can put the complexity up front but that complexity can provide a useful structure and become a leverage for serious students. For example the following is a blues scale practice from the
excellent guide by David Berkman. It'll probably give nightmares to some of the more chord-scale-phobic members of the forum. He comes up with many interesting practice ideas from these scales such as voice leading single note with minimal movement through the form. Many of these types of exercises are also very ear focused.
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Generally it's good to be skeptical of positions that outright reject ways of working on this music that's adopted some of the very accomplished educators/musicions even if it's just what you want to hear and it fills your heart with joy.
“Shearing style”
Today, 05:26 PM in Comping, Chords & Chord Progressions