Using Guide Tones
Guide tones are extremely useful when writing a song arrangement, as they make for economical writing. By using only the guide tones, you leave space in the music for other instruments, and the music becomes more precise. In general, the bigger the band, the less notes in each musician's part. E.g. the bass will usually play the root of a chord, so there is no need for a two part horn section to repeat that note. The 5th doesn't indicate major, minor or dominant chord quality, so it can also be left out.
Here is a two part Funk part using the guide tones of the chords C7 (E and Bb), F7 (Eb and A), and G7 (F and B). These are chords L [ and V in the key of C played as dominants - as in a Blues. The part is created by simply playing the guide tones and adding a rhythm which works in the musical context.
An effective way of varying a guide tone based part (or a full chord) is to approach it from a semitone below or to deviate from the chord temporarily by a semitone in either direction, before returning to the chord tones. This is called side-slipping. Here is an example based on the previous part.
This example shows two guide tone lines for II V I progressions. Notice how the 3rd of one chord becomes the 7th of the next chord and vice versa. In the first half# the 7th is above the 3rd, while in the second half, they are reversed. The choice of which note is on top is up to the player, depending on the musical context.
Using guide tones makes it possible to create smooth chord progressions. The 3rd of one chord often progresses to the 7th of the next, and vice versa. In the case of a m7b5 chord and a dim7 chord, the 5th can also be a guide tone, but in major, minor and dominant 7ths# the 5th can be omitted.
