‘Function’ refers to the positionthat a note occupies in a scale, interval, or chord. It is expressed with Arabic numerals; 1, 2, 3, etc. for note functions. It may also refer to the position a chord has within a key and expressed with Roman numerals; I, II, III, etc. Thus, ‘E’ is the 3rdof the ‘C’ major chord, i.e. it functions as the 3rdof the ‘C’ major chord, etc. The terms ‘triad’, and ‘seventh-chord’ are used, but must be used sparingly. A ‘triad’ is defined as a three-note chord. But the chord ‘B-F-G’ is not a triad. A seventh-chord is defined as a four-note chord with a 7thadded. But the chord ‘B-F-G’ is not a four-note chord, and where is the number 7? These are but a few of the inconsistencies found in music theory.
‘Scale-tone seventh chords’ are chords built on the notes of the major or minor scale. Each chord has its own identity depending upon its position (function). Thus, a seventh-chord built on the first degree of the ‘C’ major scale is indicated as ‘I’. It is a major seventh chord. A chord built on the fifth degree of the ‘C’ major scale is indicated ‘V7’. It is a dominant seventh chord. However, these indications are in no way indicative of their chords identity except coincidentally. ‘I7’ is not the symbol for ‘major’ any more than ‘V7’ is for ‘dominant’. These indications are functional indications only, with their identities merely coincidental within a major or minor scale.
Lower case Roman numerals – ‘ii’, ‘vii’, etc. are an unfortunate effort to indicate both a chord’s function and its identity. But ‘vii’ isn’t minor, and ‘ii’ in a minor key isn’t minor, and ‘V7’ isn’t major. There are so many inconsistencies in music theory that it is difficult to enumerate all of them.
Ralph Carroll Hedges, B.Ed., B.Mus., M.M.
The word ‘dominant’ must have two definitions; 1. The fifth note of a scale indicated with a number five. 2. A chord identity with characteristic intervals of a major 3rdand a minor 7thindicated with a symbol ‘x’.