Harmony
 

Melody is the horizontal aspect of music, harmony is its vertical aspect.
Harmony is melody's support and anchor. Harmony is the notes that lie
underneath the melody, giving the melody a context. The same melody
can be played with different harmonies yielding astonishingly varied
results.

Melody may be the most memorable aspect of music, but harmony is
what gives music its atmosphere. Because harmony involves fitting notes
together, most musicians spend many years studying the "rules" of
harmony. Because of this, harmony is sometimes thought of as a mere
skill. Actually, writing a good melody takes as much skill as harmony
needs inspiration!

Melody and harmony work together and are, in fact, inseparable. We
may think it is easier to isolate a melody from its harmonic "context," but
taken out of that context, the melody may have an entirely different
character. It is important to try to listen to the harmony as an equal
partner to the melody, and to identify the role that the harmony plays in
the musical work.

Harmony is very expressive, and like melody, can be used to help
represent the specific meaning of words in a vocal composition. Harmony
is as important a part of "text painting" as melody is. Most often (though
sometimes less obvious to the ear), harmony creates an atmosphere that
complements the words being sung.

In this excerpt from Bach's Cantata BWV 21, the tenor sings: "Rivers of
salty tears Ceaselessly flow and stream. Storms and waves assail me."

The agitated meaning of these lines is expressed both by the churning
melodic writing and the aching, subtly dissonant harmonies.
 

          Bach: Cantata BWV 21
          (MPEG-2, Filesize: 121K)
 

Of course, harmony is used to create character and atmosphere even if
there is no text. Listen to the following excerpt from Sibelius' tone-poem
Finlandia. In this work, the composer creates an anthem-like tune and
supports it with harmony that gives the simultaneous impression of
richness and purity. This effect is perfect for the work, which Sibelius
composed as a patriotic homage to his homeland.
 

          Sibelius: Finlandia
          (MPEG-2, Filesize: 119K)
 

Now, for comparison, listen to this excerpt from the first movement of the
Second Piano Concerto by Sergei Rachmaninov.
 

          Rachmaninov: Second Piano Concerto
          (MPEG-2, Filesize: 119K)
 

Notice that both examples feature rich harmonies, yet the effect is entirely
different. Can you describe the difference? In the Sibelius excerpt, the
aspiring nature of the melody was complemented by the unique character
of the harmony. How do the melody and harmony go together in the
Rachmaninov excerpt?

As with melody and each of the other fundamental parts of music, analyze
what you are listening to by asking questions. The purpose in asking these
questions is always to try to characterize the music:

How would you describe the harmonies? Are they lush, simple, exotic,
radiant, or somber? Do the harmonies seem to change frequently, or do
they seem static? How do the harmonic character change as the piece
progresses? How does the harmony complement the melody/melodies?