It is to these students that this essay is dedicated. Theory is a necessary background for effective sight-reading. In fact, sight-reading may even be regarded as applied theory. One needs to be very familiar with formal recognition, intervals, keys, scales, chords, melodic structure, and on-sight analysis. It is also helpful to be familiar with the grammar of music, the principles of voicing, voice leading, harmonic progression, and counterpoint.
Music theory attempts to simplify the complexities of music.
It seeks to find general organizational principles and patterns of symmetry. A chord is an example of a pattern that is taken for granted today. But, it took a theorist in the sixteenth century, Gioseffo Zarlino, to discover the major triad. Scales, keys, tonality, and modes are also patterns that come under the heading of theory. These are the basic elements of sight-reading that must be thoroughly mastered.