5 – Western Music Systems – How scales are used to compose music (Melody and Harmony)
The first dimension of music is the melody or the tune. Melody is a pleasingly ordered set of notes chosen from the selected scale. The notes are strung together so as to create tension and then to release the tension created. Tension and release are also created by the way the notes ascend and descend. The way the notes are ordered also induce consonance and dissonance between the notes.
Melodies usually start out on a note called the tonic (the root note of the scale. For example, C of C major or the G of G major scales are the root notes or tonics). The root note is in consonance with the third note and the fifth note of the major scale (major third and perfect fifth) but is in dissonance with the note that is a semitone lower than the fifth (diminished fifth or tritone). For example, C is in consonance with E and G but in dissonance with F#. Consonance produces a pleasing effect, while dissonance produces a disturbed or sad emotion. C and E or C and G sounded one after the other sounds good, but C and F# one after the other produces a very dissonant (an almost evil) effect. Try these two combinations on a keyboard or a guitar and see the effect for yourself. (The title theme of the ‘The Simpsons’ has this eerie feeling because it uses the tritone).
[The main reason why a major third (four semitone interval) produces a happy feeling but a minor third (three semitone interval) produces a sad feeling, has to do with the harmonics produced when you sound a note. These harmonics run at double, triple, four times etc. frequencies of the main frequency of the sound. Though the harmonics are not very loud, they are still there in the background. So, when you sound the note C4, the next harmonic is C5 (double the frequency), then G5 (three times the frequency), then C6 (four times), then E6 (approximately 5 times) etc. When you play the next note after C, if the note combines without interference with the harmonics you get a pleasing sound. So, a G or an E after C sounds more pleasing than some other note as some of the other notes interfere with the harmonics and create a displeasing sound.]. The third note in a major scale (four intervals away) thus is consonant with the root, while the third note of the minor scale is in dissonance. This is why a major scale sounds happy while a minor scale sounds sad.
Note that different instruments and different voices produce harmonics of notes differently. In some instruments even-numbered harmonics (2,4,6 etc.) are more present than than odd-numbered, while in others odd-numbered harmonics are more present. There may also be differences in the audibility of these harmonics between different instruments and voices. Also, some instruments and voices emphasize the harmonics more than the fundamental sound. These differences contribute in a big way to what is called the timbre or the tonal quality of the sound. There are other factors also that affect timbre, but we will not go into details here.]
Consonance and dissonance also play a great part in harmony. Chords of music (triads) which are three notes played together have the function of creating these moods. A major chord has the root, the major third and the perfect fifth sounded together (that is, for example, C, E and G) and therefore creates a happy feeling. A minor chord on the other had has the root, the minor third and the perfect fifth sounded together (C minor chord, for example, has C, E♭ and G) and so sounds slightly more somber.
Different instruments (including the voice) played together or individually try to create these pleasing effects using melody and harmony. Harmony along with melody are the two key elements of a piece of music.
The other important thing in melody is creating tension and releasing it. The melody starts, as we said before, on the root note and when the dominant note (the perfect fifth on a major scale) is played, it builds a tension that wants to resolve by going back to the root. Similarly, the note that is one semitone lower than the root note, the seventh note of the major scale (note B in the C major chord) also creates an intense longing to resolve to the root note. [The harmonic minor scale, by augmenting the seventh note by a semitone, creates this same effect.]. Using such combinations musicians create tension and release which is the essence of music.
Melodies are created by stringing together notes in a pleasing way. Each of these notes have different duration of sounding (or singing) and different levels of loudness. Small phrases or riffs that create a pleasing effect are first created and these are then combined together, in a repeated fashion, with different developments and changes on them. These phrases themselves may be formed by shorter pieces called motifs (these riffs, motifs and phrases are what stays in your mind for a long time after you have heard a song. The opening 4 notes of Beethoven’s fifth symphony is a famous example: G G G E♭. Then, the same four notes repeated one note lower F F F D. The second note in bold of the two four note motifs are emphasised. The fourth notes in the two motifs are elongated. Listen to the first movement of Beethoven’s fifth here.) These phrases together form what is called a long section of music called the theme.
[The ‘key signature’ is a music sheet indicates the scale on which the composition is based. Each major and minor scale has a key signature associated with it. The key signature shows which notes of the music are sharp or flat, thus indicating the scale.]