Strangly, when my brother first introduced me to metal in my later years of high school I didn't really like it. The particular album I remember was Years of Decay by Overkill. During my freshman year of college Metallica's Black album was getting a lot of air play on the radio. After listening to some of this stuff I decided to buy some older Metallica albums. Thus began my journey to become a full fledged metal head. By my senior year I had surpassed even my brother's taste in terms of heaviness and I am now greatly into bands such as Sepultura, Pantera, Death, Invocator, Prong, Entombed, and of course Metallica and Megadeth.

After the initial shock of developing such radical musical tastes was over and I had visited various moshpits hosted by such bands as Metallica, Megadeth, Sepultura, Pantera, White Zombie, and Death, I began to expand and find some more mellow stuff I liked. It was about this time I started thinking about music, why people like it, why they don't like metal (most people that is), what I like about music, and why I like metal, etc...

What is metal?

One of the many amazing aspects of music is its ability to convey emotions. These emotions can even change throughout the course of one song. Nearly every song classified as metal deals with emotions such as anger and aggression.
But how are these emotions conveyed? I believe there are three main aspects: the notes, the sound, and the rhythm.

Most music has a dominant rhythm instrument or sound that carries the song along. This may be piano or synthesizers, accoustic guitars, clean or distorted electric guitars, bass, horns, string instruments (violins, etc), or even backing vocals. Although I'm not sure quite how, the dominant instrument has a definite effect on how music is perceived.
The selection of notes and key changes also affect the feeling or mood of music. A simple example of this is using major or minor keys. Major keys sound happy and minor keys sound sad. Again it is unclear how these factors have their effect, but they definitely do. The 12 note scale is a human invention, but the combinations of notes to create different feelings is a discovery.
The rhythm affects the musical appeal more than the emotional content, but factors such as the arrangment and timing of notes can have some effect. The tempo of the song is also important.

Metal fits into this scheme with heavily distorted guitars for rhythm, usually a fast tempo and complex rhythm, and a lot of minor keys, though the note and key choices vary widely.

Why don't "people" like metal?

Aggression is an emotion that people in general don't like to feel. When a normal person hears metal, their mind rejects the emotional response and blocks the music from entering the analytical part of the mind. The net effect here is that to a normal person's brain, metal just sounds like noise. This effect is increased by the fact that metal is rhythm oriented and not vocal oriented. Normal people focus more on vocals, and since the quality of vocalists in metal is not what normal people expect from music, they are furthur turned off.

Why do I like metal?

First of all, like all metal heads, somewhere in the core of my being is something that likes pure, undirected aggression. Aggression is closely linked to adrenaline, which makes metal concerts an amazing experience. Unlike many metal heads, this part of my being is quite deep inside, and is quite a sharp contrast to my external personality. Second, I like the sound of the main instruments used in metal: guitars, bass, and drums, all of which I happen to play. Metal can be amazingly complex, and when the sounds and rhythms of these instruments come together in certain ways, the feeling is awesome. In some ways I feel lucky to like metal and be able to appreciate all of its qualities. Although my mind can't comprehend it, true jazz fans probably experience a similar respect for their music.

As I have expanded my musical tastes I have found many other bands and songs I like, but they usually contain at least one of these key aspects: rhythmically complex, guitar sounds, based on negative emotions. Since metal puts all of these together, that is why it is my main musical interest.

Okay, enough philosophisizing for today...

Feel free to share your own ideas and thoughts!