One of the striking differences between classical musicians and contemporary musicians is that, in the majority of instances contemporary musicians are responsible for the creation of their own parts, whereas the classical musician (composers notwithstanding) is often recreating parts, already written by the composer, and as such is focused predominantly on execution.
Of course, a great many musical skills (be they harmonic, melodic, rhythmic or technical in nature) are transferable and transcend genre, but the contemporary musician’s need to compose their parts, and often improvise them, requires a specific understanding of all of the fundamentals involved in the production of the piece, or context within which they are performing.
A great example of this is the contemporary musician’s need to create parts, often at sight, to chord charts. In order to do this, the contemporary musician not only needs to have transferable skills such as great tone, time and control of dynamics, but also an advanced and practical understanding of the appropriate harmonic and rhythmic nuances of the piece.
Here’s a harmonic example:
A G7 chord resolving to a C major chord has an abundance of potential scales (Mixolydian, Lydian Dominant, Half-Whole Diminished, Altered Scale, 5th mode of Harmonic Minor and so on) from which the performer may create stylistically appropriate parts.
The experienced performer knows, and can hear, which the most viable options are, based on the stylistic demands of the piece and needs to have developed a suitable vocabulary from which to compose and execute a broadcast-quality performance.
This practical, harmonic knowledge is often best developed from learning and applying content either
- a) devoid of context. an interval, chord or scale at a time, until all relevant chords, scales and their functions are learnt
- b) within a context. transcribed from, and applied to, compositions.
The essential study of the stylistically appropriate harmonic, rhythmic, melodic and technological fundamentals is the study of Popular Music Theory and will teach not only the component parts, but also give multiple examples of their application.