Music Theory - Definitions

Table of Contents

Definitions referenced in other pages.

Intervals

On the staff, notes are connected by intervals. Given the size of the interval, different names are given to a sequence of two notes:

STEP 2m, 2M
SKIP 3m, 3M
LEAP ≥ 4

Consonance

Inside the diatonic scale, we find consonant and dissonant intervals. One of the ideas of counter-point is to build a beautiful and interesting melody by using only consonant intervals upon metric accents (this is more detailed in here).

Consonant

Perfect Intervals Unison, Melodic 4, 5, 8
Imperfect Intervals 3, 6

Dissonant

Diatonic 2, 7
Not diatonic 5dim

Motion

It’s the idea of the vertical direction two melodies take in a counter-point (e.g. do melodies separate from each other or do they get closer?). Again, some motions are preferred in counter-point, because they embellish the melody and make it more interesting.

Contrary

contrary-motion.png

In contrary motion, both melodies move towards each other or in opposite directions.

This is the preferred way of motion in counter-point.

Oblique

oblique-motion.png

This one is to be avoided.

Parallel

parallel-motion.png

Moving by the same interval.

Allowed between imperfect consonances.

Similar

similar-motion.png

Same kind of motion but with different intervals.

If landing on a 5, the upper voice approaches by a step.