What are inner and outer voices in music of late 20th century and 21st century?

Question

In many textbooks voices are classified as inner and outer. Outer voices are the highest voice (soprano) and the lowest voice (bass), and the inner voices are all the other voices that are between the two outer voices. This classification is very important because the rules of counterpoint, voice-leading, harmony and other disciplines are very different for those two kinds of voices.

The rules for inner voices are more sparing, easier, simpler: the leading tone in inner voice does not have to be resolved, dissonant intervals are less disturbing in inner voices and so on. Therefore most of the composer's labor comes from the interaction between the outer voices.

In textbooks and other resources determining outer and inner voices is easy because the resources and books usually use piano examples with up to four simultaneous voices. But how do I determine the inner and outer voice in complex real-world music, like orchestral music with dozens of instruments, modern music of 20th and 21st centuries with many guitars, keyboards and ambiguous theory? Are the leading melody and the bass in the modern music the outer voices, or the vocal line and the bass?

Answer 1

how do I determine the inner and outer voice in complex real-world music, like orchestral music with dozens of instruments?

For most traditional orchestral works, this will be clear. The dozens of instruments typically participate in a four-voice texture, or perhaps five or six, through a technique known as "doubling": when everyone is playing at once, for example, the flutes and oboes and first violins are all playing the same notes, perhaps in octaves, but this tends to be the melody. The cellos and basses and bassoons all play the bass line, almost always in octaves. Sometimes, cellos or bassoons, especially the first bassoon when the bassoons divide, will move to the tenor part. These moments are generally obvious.

In later music, innovative orchestration started to move away from four-voice textures. When the music isn't written in a traditional homophonic or contrapuntal texture, it may be difficult to identify the "outer voices" but that's only to be expected, because the term ceases to have meaning in such a context.

If by "modern music" you mean to include music that can be presented on a lead sheet, that is, a melody with chord symbols, then the melody and the bass line (specified by the chord symbols) are, as you suggest, the outer voices, but the rules of voice leading are not applied strictly in this context, and there often aren't so much inner voices as just, well, chords.

Of course, there is also a lot of modern music that lacks harmony altogether, and even pitch. You mention "ambiguous theory." For much music, the question of identifying outer voices is meaningless. I'm thinking of any unharmonized melody, or of rap, or of pieces using only unpitched percussion such as Steve Reich's Clapping Music.

Answer 2

When writing chorale-style for 4 equal voices, 'inner' and 'outer' are terms that mean something. In other styles and textures, not so much! And that's fine. Know how to harmonise a hymn tune, Bach-style. Know how to write a melody plus an accompaniment. Maybe there will be a strong melodic bass line, maybe a simple 1-5 vamp. Maybe there will be an internal counter-melody, maybe a rhythmic guitar strum. No need to beat yourself up looking for 'inner voices' when there aren't any!

Answer 3

Inner and outer voices don't change because of instrumentation. Outer voices will always be the highest and lowest parts of homophonic music regardless of what instruments are playing those parts. Inner voices will be everything else in between.

The reason for the inner/outer voice distinction is because of the homophonic musical texture. The concept changed a bit over time, basically the "common practice" period, but homophonic texture essentially means melody with chords or melody with bass. A full description can't be given in a short answer, but homophonic music in very broad terms is a background structure of tertian chords decorated with melodic figuration. Stylistically the bass emphasizes chord roots in its lines compared with the more freely moving top part. That is how the bass realizes its important harmony defining role in homophonic music.

It does not matter what musical era you look at, if the music is homophonic, then the outer voices have primary importance. Modernism includes examples of homophonic music. You need to examine each piece of music to determine whether it is homophonic. Actually, you should examine each passage of music to determine the texture. In "classical" style and Modernism texture can change from phrase to phrase and either style may use various textures: monophonic, parallel, contrapuntal, homophonic, etc.

Satie's Gymnopedie and some of Bartok's dances are good examples of Modernism using homophonic texture with bass and melody plus harmonic filler. You can also find example where the texture changes within the piece. Satie's Ogive use monophonic, quasi-parallel, and homophonic texture in combination. Debussy's music is famous for parallel texture, but sometimes has moments of homophonic texture. Girl with the Flaxen Hair is an example. All of those examples I mention are piano music, but the same treatment of texture will apply to instrumental genres. Actually, some of those piano examples are popular enough that they have been orchestrated. The orchestrated versions should offer good models of modernism, fully orchestrated, but with homophonic texture.

...But how do I determine the inner and outer voice in complex real-world music, like orchestral music with dozens of instruments...

Many textbooks provide musical examples that are piano reductions of orchestral music. You should take a similar approach when analyzing orchestral music. Determine whether the music at hand homophonic in the first place, isolate the main melody and bass, be aware those could span over instrumental changes, filter out what is harmonic filler and orchestral coloring. Especially for the melody do not always assume the highest part is the melody. It's very common orchestral filler/coloring to be high registers above the actual melody, and to double parts in a higher octave.

I suggest doing this first with simpler Haydn and Mozart symphonies or divertimentos, even their orchestral dances. In those cases you can usually see easily the winds and horn adding filler/color/doubling while the main melody and bass and most often in the strings. In cases when the winds or brass get the main melody, you might see the strings drop out for a while.

Get comfortable with reading those classical orchestral scores then move on to appropriate modern homophonic orchestral (and perhaps larger chamber ensemble) music. The composer Poulenc may be a good one to check out. He was considered a sort of "Mozart" of modernism and his music will include homophonic type textures. You should see lots of examples of homophonic outer voices at play, and then you could compare it to a score like Stravinsky's The Rites of Spring to see a lot of not homophonic music, just to make clear the difference.