Using Modes for Improvisation

In the previous section, we defined all sorts of modes; we will now discuss how they can be used in practice: improvisation (in this topic) and composition (in future topics).

Using modes for improvisation requires that you clearly understand the relationship between modes, scales and tonality.

One of the dominant features of modal (church) music in the Middle-Ages is the fact that it was purely monodic (a single melody line sung at unison).  In the late Middle-Ages, with the birth of counterpoint (several melodic lines sung simultaneously but independently), and at the Renaissance when music became downright polyphonic (several melodic lines simultaneously at rest to form chords), the modes were gradually abandoned and replaced by the tonal system.  However, two modes were kept: the Ionian mode (major) and the Aeolian mode (minor).  The Aeolian mode itself further evolved (for tonal reasons) to give birth to the harmonic minor scale and later the melodic minor scale.

In contrast, most traditional musical systems in the world have kept the modal characteristics, and are still modal, even today.  This is notably the case of the East-European music, African music, Indian music, Chinese music, and so forth.

As said, the original modal music was monodic: each song consisted of a single melody played or sung at unison.  There were no chords.  The melody was more or less free to move, but severe rules would impose specific cadences (depending on the mode being used).  One of them was that any song should always terminate on the tonal centre, or finalis.

Later, music gradually became polyphonic, and that changed the picture completely.  By definition, a chord consists of several notes played simultaneously.  However, notes have a variable affinity with each other; when played together, some combinations of notes seem to produce a feeling of rest and fulfillment, while others seem to flee each other and require an urgent resolution onto a more relaxing combination.  Careful observations of this phenomenon, along with fashion effects and cultural habits have progressively resulted in the theory of harmony, rooted in the so-called tonal system (see Intermediate Theory).  In this system the tone center is imposed by the chords and their progressions.

The more rich and complex the chords, the more strictly defined the mode will be.

This has two dramatically important (and often overlooked) consequences:

•       When playing lead on top of a harmonic background, the actual fingering pattern (scale pattern) used by the lead guitarist has typically little or no effect on the mode of the song (since the latter is imposed by the chord progression).  Put differently: the mode is decided upon at composition time, not at improvisation time.  If the song is in C major, the fact that you start the C major scale on a D does not mean the song now all of a sudden becomes D Dorian

•       When playing harmonised modal music, the rules governing chord progressions will have to be different in order to escape from tonal habits

Over any chord or chord progression you can always use any scale pattern (fingering pattern) that is compatible with it; depending on this chord progression, you may in fact have more or less flexibility in choosing the appropriate scale pattern(s).

•       with diatonic four notes chords (and more), you will usually have no choice other than that imposed by the chords

•       with triads, you may have more flexibility

•       with power chords, you will typically be able to pick several compatible scale patterns; in that case the notes you decide to play will have a large impact on the harmonic color of the music