Among the most useful concepts in jazz theory is the idea of guide-tones. 

A guide-tone is a melodic line composed of one or two pitches extracted strategically from each chord in a tune. It is the idea that if you distill a chord down to its essence, you can create a melody that outlines the harmonic progression of a tune in no time at all.

In the process of elaborating on the guide-tone melody, embellishing it, and decorating it, you can create a rich and creative musical vocabulary while clearly referencing the chord changes.

3rds and 7ths of chords are often and effectively used as guide-tones. 

Guide-tones like 3rds and 7ths can be used to distinguish the three most common types of jazz chords: major, minor, and dominant 7th chords.

Using Bb rhythm changes , here is an example of how guide-tones can be visualized.

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