Harmony Principles 2014 Sun Music Center Ltd., CANADA Voice Leading Voicing Prior to addressing voice leading, one should consider voicing strategies in 4-‐part writing. In terms of note distribution and doubling, follow these guidelines: With root position triads: double the root. With first inversion triads: double the root or 5th, in general. If one needs to double the 3rd, that is acceptable, but avoid doubling the leading tone. With second inversion triads: double the fifth. With seventh chords: there is one voice for each note, so distribute as fits. If one must omit a note from the chord, then omit the 5th. The main concerns of composers writing homorhythmic, homophonic music were both unity and independence. This seems contradictory at first. However, unity is a vertical dimension concern (the chords), while independence is a horizontal concern (the lines). Each of these concerns is addressed in principles of voice spacing. To achieve sonorous (unified) chords, one wants to do the following: Never have more than an octave between adjacent voices in the upper three voices (SAT), Never have more than a 12th between the bass and tenor. To achieve independence of lines through spacing, one wants to mainly avoid voice crossing. For example, the alto shouldn't go below the tenor or above the soprano in a chord; tenor should never go below bass, etc. The other strategies to reinforce independence are found in the voice leading strategies below. There are two approaches to voicing a chord with 4 voices: open structure and close structure. With open structure, the interval between the upper three voices (SAT) is greater than an octave. With close structure, the upper three voices fit within an octave or less. One way to think about close structure is that it places the upper three voices next to each other on adjacent chord tones. This doesn't always happen, but it is frequently the case. Harmony Principles 2014 Sun Music Center Ltd., CANADA Keyboard Voicing The above principles for voice spacing of SATB more or less apply to keyboard voicing. There are some differences worth noting though. The most obvious is that, with keyboard voicing, one places 3 notes on treble staff and 1 note in the bass. Also, close structure is most frequently encountered because the 3 notes on the treble staff are to be played by a single hand, and hands don't generally stretch much more than an octave or tenth without some form of assistance (like a medieval torture device). * Doubling of the leading tone is bad practice in general when trying to emulate this style of music. It isn't seen much. What the reason for this? Some say composers avoided it so that the leading tone wouldn't be overemphasized. On a more practical level, since the leading tone tends to resolve to the tonic, two leadings tones would both resolve to the tonic at the same time, forcing parallel octaves (see below as to why that's to be avoided). Principles of Voice Leading The principles of voice leading can be summarize as follows: Keep common tones, Move voices by step, if possible, If you can't move by step, move by smallest possible interval, Use contrary motion, if possible. There are, however, more specific rules used in late 18th century music, particularly with a homorhythmic, homophonic texture like SATB chorale writing. These include: Avoid parallel fifths and octaves, as well as fifths and octaves by contrary motion; Avoid doubling the leading tone; Harmony Principles 2014 Sun Music Center Ltd., CANADA Avoid hidden (or direct) fifths and octaves; Avoid using the +2 interval melodically. Below are some illustrations of these "sins". Luckily, at least with root position chords, there is a set of algorithms that can be used to create stylistically accurate voice leading. These really only work with root position chords in SATB writing. Once inversions are introduced, there are too many possibilities and considerations. The algorithms for root position chords are given below along with musical illustrations. For chords a fourth or fifth apart, there are two approaches: a common tone approach and a non-‐common tone approach. With the common tone approach you: Move the bass to the root of the next chord, Carry over the common tone from the previous chord, Move the remaining voices by step or smallest possible interval, Try to incorporate contrary motion. With the non-‐common tone approach you: Move the bass to the root of the next chord, Move all of the remaining voices to the nearest chord tone of the next chord, Try to incorporate contrary motion. Harmony Principles 2014 Sun Music Center Ltd., CANADA For chords a third or sixth apart: Move the bass to the root of the next chord, Carry over the two common tones from the previous chord, Move the remaining voice by step to complete the chord. For chords that are a second apart: Move the bass to the root of the next chord, In contrary motion to the bass, move the remaining voices to the nearest chord tone of the next chord.
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