A focus on discord and resolution is, I believe, one of the most useful approaches for the beginner improviser. Of course, discord and resolution are dependent upon harmonic progressions but there is no need for the beginner to know why certain combinations of sounds create dissonance while others are concordant.
What creates tension will vary from one culture to another, and from style to style. However, most of us have heard so much music that we instinctively feel the tension and discomfort of combinations that demand resolution in our genre. This constitutes one of the biggest barriers to beginning improvisation – the fear of ‘wrong notes’. So, it’s very useful to set up situations in which discords are bound to happen and the beginner can learn that they can resolve them. This can have a very liberating effect on the approach to improvisation.
It’s easiest to follow instinct when working vocally and, for those who sing, this is a good place to start. For a group, a fun exercise is for each to sing, at a signal, a random pitch.. After walking around the group for a few seconds, trying to hold the pitch, a new note can be chosen. Participants should listen to their pitch in relation to that of their closest neighbour, sometimes adapting to blend with it.
The pentatonic, gapped, scale is often recommended for beginner improvisers because the lack of semitone relationships between the notes of the scale removes the strongest dissonances. This scale is equivalent to a major scale with the fourth and seventh degrees omitted. This builds confidence and the scale is very common in folk music of many regions and in jazz. Although there are no really harsh sounds when combining parts using a pentatonic scale, some things will sound better than others. Where desired, greater consonance will usually be achieved by dropping to the note below. The improviser can focus on shaping the melody, without disconcerting harmonic clashes.
The confidence gained from working with pentatonic scales can be applied to major scales. Just as with the vocal exercise, a pupil can sound a note of the scale, at random, on the first beat of the bar, as the teacher/accompanist plays a chord. If the pupil is comfortable with the pitch they are sounding, they can hold it for the rest of the bar. If not, they can drop to the next lower pitch of the scale on the second beat of the bar. If the discordant note is the leading note of the scale, they should rise to the tonic on the second beat.
Another exercise I use is to teach a tune, made up entirely of whole notes, based on notes of tonic and dominant seventh chords. Pupils are then asked to precede each note with the note above in the scale, dropping to the chord-tone on the second beat. Likewise, each note can be preceded by the note a semitone below, resolving up on the second beat. The pupil can then experiment with various combinations of chord-tone and upper or lower appoggiatura. After a little experience of these exercises, discords are ‘no big deal’.