However, this style of improvisation can begin to feel limited or restrictive after a while. Musicians who have been improvising for some time may find themselves desiring a wider range of pitches to add to their vocabulary. They desire to introduce pitches that are chromatic to the harmony they are improvising over. One way to accomplish this is through the use of approach note theory.
Last week we discussed neighbor tones, passing tones and how they relate to target notes. These concepts form the fundamental ingredients of approach note theory. The chord and scale tones that we were using in our beginning level of improvisation become the target notes for this style. Instead of stringing diatonic pitches together to form melodies, we approach these pitches with chromatic neighbor and passing tones. The root, third, fifth and seventh tend to work best as target notes since they are strongly related to the harmony and balance out the sound of the unrelated chromatic pitches. However, the other pitches of the scale can also be used depending on the context. Repeating motifs and other elements that have strong melodic pull can often compensate for weaker harmonic relations.
There are two additional factors that govern the successful use of approach notes. They are rhythmic duration and beat placement. In general, approach notes tend to have shorter rhythmic values and are placed on weak beats. Of course there are always exceptions to the rules. Approach notes can also be placed on strong beats for brief moments within some musical contexts. In addition, this rule does not mean that all target notes must be long in duration. Some intricate lines may contain several eighth or sixteenth notes that are a mix of approach notes and target notes. However, these types of lines usually resolve with a longer tone that is a target note.
Another exception would be the use of a longer tone that is held over from a weak beat to a strong beat as an anticipation. In this instance, the pitch would be chromatic to the harmony on the weak beat but diatonic to the new harmony on the strong beat. It functions as an incomplete approach that anticipates the new harmony and transforms into a target note.
There are many possibilities, and it would be exhaustive for me to attempt to describe them all. The point is to start our journey into this type of improvisation with following the rules, and once we are grounded in basic approach note theory we can look for ways to expand by bending the rules. With the introduction of approach notes to the vocabulary of improvisation, we will find access to a vast variety of melodic expression.