Chapter Three

Recognizing whether intervals have been increased or decreased in music is not as easy as you might think. For example, look at the following gif. Has this interval been increased or decreased? There is a good chance that it has been decreased. Why do we think so? We assume that the lower note is the keynote of a major scale. Thus, the keynote of the scale is E. The higher note is C. In the key of E, we know that C is sharp. However, in our example, the C is natural. Thus, this interval has been decreased in size (it is minor).

You may think that it has been easy going so far. However, you are now going to have to turn down the volume on the music you're playing and focus on the subject at hand. We are going to discuss the inversion of interals.

When two or more instruments play together, they often have their own melody. You have obviously witnessed this in an orchestra. Classical music, and all other music for that matter, would be one diminisional and uninspiring if all instruments played the exact same notes all the time. Futhermore, the piano is one of the few instruments that allows the musician to play two melodies simultaneously. As the notes are played together, they create certain intervals.

Inversions occur when two instruments, or two melodies on a piano, are alternated. For example, a saxaphone may play C, C, D, while the guitar plays E, F, F. When the inversion occurs, the saxaphone would play E, F, F and guitar would play C, C D. The following link is to a prelude by Bach. Compare the initial five eigth notes in the first measure with the inital five eigth notes in the fourth measure. The initial five eigth notes in the first measure are C, E, F, E, C. The initial five eigth notes in the fourth measure are C, E, F, E, C. They are the same notes! This is an example where the notes were inverted from the treble clef to the bass clef. It is obvious that the exact inversion of the notes does not continue consistently throughout the remainder of the music. Undoubtably, an exact inversion would not have led to such a beautiful piece of music, and who are we to second guess Bach. Remember, Bach was to music what Einstein was to physics. Nevertheless, it is apparent that the melody is very similar whether the eigth notes are on the bass clef or treble clef. Furthermore, the intervals between the notes is very similar whether the eigth notes are on the bass clef or treble clef.

Bach Prelude 2 Sheet Music

Bach Prelude 2 Midi File

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