Swedish trombonist Anders Larson has a blog called Digital Trombone about, as you might imagine, trombone playing. He’s got a lot of exercises on scales and chords that would be particularly useful for jazz players.
His latest post contains pages of triad exercises. I’ve been thinking about triads for improvisation lately (see this recent post of mine) and Larson’s exercises are good for practicing different triad patterns.
One of the sounds I like the most utilizing triads is superimposing a triad that doesn’t contain the root of the chord. Here are four examples.
Playing a G major triad over a Cmaj7 chord will get you the 5th, 7th, and 9th of the chord, but the triad has such a strong harmonic implication that there’s still a bitonal implication in spite of how “inside” that triad is to Cmaj7. The G minor triad over the C7 chord is the same. B flat major over Cmin7 gets into more upper chord extensions, the 7th, 9th, and 11th. All these pitches are very consonant to the chord, but the root of the triad is an upper extension of the sounding chord (B flat is the 7th of the C chord, as opposed to the 5th). The resulting sound has more color.
The most colorful of my four examples is using an A major triad over a C7 chord. The resulting pitches still relate to the C chord, in this case the 13th, flat 9th, and 3rd. Even though two out of three of those pitches (A and E) are very consonant to a C7 chord, this triad sounds quite bitonal. I think this may be related to how distant the key of A major is to F major (F major is the diatonic “parent” key to C7, see this post on the modes for a quick intro if this doesn’t make sense).
As always, don’t just practice these as mere licks to memorize, really listen carefully and memorize the sound that they have. When you’ve assimilated the sonic color of superimposing different triads over particular chords your improvising will be free to go in this direction when you feel it fits.
Be sure to also check out Larson’s blog for more on this topic, and many others.