The three pillars of music
As music has three causes, it is also sustained by three pillars, each having its own three causes. Those are melody, harmony, and rhythm. A music that lacks one or more pillars, or has unbalanced pillars, is destined to be transitory (a temporary fashion) and does not win the test of time.
Melody is the first mover, which gives the entire meaning to a piece. It is a severe resolution, determining the message of the piece. The human ear, from a psychological point of view, while listening to music, is capable of distinguish only a single main tune, and thus melody. It is not important how complex the harmony is, but the mind has a single threaded operating mode and makes the sum of everything to get a grasp of it. Only when the mind is trained, such as that of a conductor, it is possible for it to work in multi threaded mode, being able to distinguish among instruments and melodies played at the same time.
In Italian, "me-lo-dia" is a pun meaning "give it to me". A man would say that to a female performer, to ask her to give him love - i.e. her genital organ. That would usually raise a smile. However, to be strict, "lo" is in the male form. So, it should be the woman asking the man. The reason we are mentioning this here is that the component of music we are likely to fall in love with is melody. When it touches our inner chords, it is like being in love, or making love. Attributes such as "sensuality", "warmth", etc., all stem out of melody. Remove it, and music becomes dull and void. It loses all its splendor and persuasion ability. We instantly perceive a feeling of heaviness, intolerance, rejection.
Melody is an instrument, which needs to be played to effect something. We resonate with it- i.e. we like it - because we have the same chords, and not because its interpretation astonishes us. It can be badly performed, but our mind would add the missing elements and complete it anyway, if we are really in tune with it. This is a little like Michelangelo's philosophy: He did not complete the last details of his sculptures, such as the hair, purposefully, because he knew the human mind would complete them. He was just providing the blueprint, allowing the viewer to become the instrument itself. The artist became the co-creator with the one benefitting from his inspiration. As a result, the artist, even after death, could come back and live again. His thought would merge with the that of his public, expanding it with new meanings, compatible with new ages. Therefore, he would reach immortalilty.
Harmony, as we are taught, completes melody with a mathematical construct of sounds. It acts a merciful giver, or filler. It establishes melody, gives it its dimensions and directions, fights with it when needed (counterpoint, etc.). Despite harmony is meant to reverse the dominant effect of melody by creating a number of parallel musical lines, it achieves only to strengthen it and widen its scope. It comes to wreak havoc and instead it acquires a mathematical rigor that goes hand in hand with it. Like the first two causes of sound, melody and harmony fight together. But their fight has also the character of love, as one follows into the footsteps of the other. They seem intertwined in a mortal dance that, instead, gives them life.
In order for them to run their show, they need a frame, which is given to them by rhythm - i.e. a timeframe. Rhythm marks their flow and unfolding, being their battleground. We need to specify that rhythm, here, is not intended as drum beats, which are an entirely different thing. We refer to the natural rhythm of a music, which is indicated as the time in the score. Without rhythm, we would not be able to distinguish the "words" of the musical message. It is rhythms that lets them become evident in all their simplicity and beauty.
Rhythm is given by the subdivision of a beat in a variable number. We can have a beat in 2, 3 , 4, etc. Nonetheless, the beat always always begins with a downbeat and has an upbeat in its middle. The downbeat leads the dance, so to speak. It is like a dancer hitting the ground with his foot - i.e. it is accented. After the foot touches the ground, it cannot go lower. It must raise. Therefore, the next thing is an upbeat, where the foot reaches its maximum height in the air. There is no accent here, and nothing is hit in the air. Thus, music reaches its lowest volume at this point, but charges in energy. This energy is then discharged with the next downbeat. This cycling repeats over and over, imitating the nature of sound itself being an oscillation.
At the side of the base rhythm, we have a more complex one, which alters and influences the former. The flow of musical lines is regulated by phrases, which are indicated by ligatures in the score. Despite a downbeat is always accented, if the musical line spans along many beats, it would be a crescendo in its first half and a diminuendo in its last half anyway. It charges in the first half and returns to rest in the second one. All is like a breath - inspiring and expiring.
Ancient seamen defined the waves of the sea as having three components: Flux, reflux, and deadlock. Flux is when the the wave starts forming and rises upward, at an increasing speed. At a certain point, it starts falling down, going below sea level, as to make a wave inside the sea, opposite to the one that was above. That is called reflux and involves a slow down. The deadlock is simply the starting and end point at sea level, which has no energy. This is just another description of an oscillation. However, it is a nice image for the performer to think when he is interpreting musical phrases. Music is not supposed to be plain, flat. Instead, it must reproduce what it is meant for, always. When the correct interpretation is given, music becomes like a beating heart - i.e. living. This is perceived at once by the public, which grasps and responds to it more promptly.