Using Triads and Arpeggios in melodic playing explained in 5 levels of difficulty.
Triads are the building blocks of Harmony; giving structure to compositions, creating moving dissonance, or consonant stability. However, triads and arpeggios also form an interesting part of melodic composition or improvisation. Using certain patterns and phrases with scale tone arpeggios makes it very natural to weave them into playing or compositions without sounding mechanical or dry.
The first technique, simply using triads, is to play them ‘end to end’; the first triad (ex.1) starts on C, playing the C major triad CEG. The next triad in the key of C major is D minor, but instead of starting on the root D and moving up through the two remaining notes, we step up one letter to A, (the fifth of the D minor triad), and reverse direction and continue down through F and D. This change in direction breaks up the monotonous sound of consecutive triads and can be broken up in countless other variations.
An addition to this technique is to add the 7th of the triads as you play them. This should be practiced or visualized in the standard order (ex.2) before moving on to use the ‘end to end’ approach (ex.3)
The next step in this approach is to add a rhythmic element to the arpeggio, to make it sound more musical, less rigid. The first rhythm I add is a triplet, and to facilitate this choice a leading tone is added to each triad. An exercise using these arpeggios (ex.4) would be played all in one direction, if reversed the leading tone no longer works and the exercise isn’t relevant (ex.5).
To take the arpeggio a step further, it’s necessary to add notes that lie outside of the usual 1-3-5-7 harmony and include the 6th of the chord. The simplest way to add this to the arpeggio is by stepping down from the 7th (ex.6). This pattern has a very melodic sound, due to the stepwise motion between the 7th and 6th of the chord. It can be played with the leading tone (ex.7) or without (ex.8), with the triplet rhythm (ex.9) or without (ex.10).
Another technique is something that is used by composers from the Baroque era to modern day musicians, that is, Octave Displacement. In the last set of examples the arpeggio changed direction at the end of each pattern, the melody falling instead of rising from 7 to 6. To further develop this idea, we can use any of the arpeggio examples and lower some of the notes by an octave, having more opportunity to change the direction of the melody. The simplest way is to start with the tonic note being followed by the rest of the arpeggio an octave lower (ex.11). You can also add the rhythmic element, and the 6th of the chord, back to the pattern (ex.12). Breaking up the notes further can also add movement to the arpeggio (ex.13)
A different way to approach arpeggios when choosing which arpeggio to use over which chord, is to use arpeggios other than the prevailing harmony. The usual way is to use a Cmaj7 arpeggio over a Cmaj7 chord, however if we look at the 3rd, 5th, and 7th of C we see that those notes form the E minor triad. What this means is the tones of the Em arpeggio, including the 7th of E, can be played over a C chord (ex.14) Another example is using an F# diminished arpeggio over a D7 chord (ex.15) which creates tension before resolving to G. Used in a I-iv-ii-V7 progression (ex.16). This leads to the idea of playing ‘outside’, meaning using a totally different key than the written chord, a half step up or down; like an Abm arpeggio line played over a Gm chord (ex.17) Hopefully these ideas help make your melodies more interesting.