Watch the Evaluate The 12 Tones online guitar lesson by Jon Herington from Ear IQ: Reactive Improvisation
The simplest, most foolproof way to discover the best sounding notes on any chord is to play each of the 12 notes against the chord, and react to each one. Does one note sound particularly beautiful or consonant against a chord? Does another note sound foreign, dissonant, or just wrong? Does one note sound particularly strong and powerful against the chord? Does another sound a little less strong, but interesting? To improvise well, and to prepare ourselves to make the most musical choices, it will help to explore the character and quality of each note against each chord, and to remember the feeling each note evokes against the sounding chord.