Metal has been always stereotyped as rough, raw and noisy music. Others don't call it music at all. What is so significant with metal is the culture that it entails; violence, rebellion, freedom of expression, devoid of pretention and superficiality. Popular antics of Metal musicians include the quintessential headbanging, insane guitar riffs and solos, and growling. People tend to overlook the technical musical affluence of Metal; from the Harmonic Minor scales and off-tempo drum patterns, that is easily one of the most difficult types of modes and similar to the technicality of Classical Music. Richard Wagner stated in the documentary "Metal: A Headbanger's Journey" that if Beethoven was alive during the time of Metal, he'd probably be in Led Zeppelin or Deep Purple. Another point about the musicality of metal is the origin of its sinister sound; the diminished fifth or tritone (known as the "Diabolus in Musica". Yeah, it's that sinister). To discuss this technicality of Metal, we go back to its deep roots, the Blues.
The Blues is a slave music, played by the African-American communities during the Emancipation to express, well, their blues. Popular blues acts include B.B. King, John Lee Hooker, T-Bone Walker and later musicians that incorporate blues are Jack White and John Mayer. With the later developing of blues, it is adopted to the classical rock where they linger on Pentatonic Scales that is blues-oriented and fundamentally the musical scale for rock music. Classical rock artists exhibit this bluesy sound, from Led Zeppelin's "Since I've Been Loving You", Jimi Hendrix' "Hey Joe" and The Beatles' "Yer Blues". Off-topic and Led Zeppelin related: the song "Me Love" by Sean Kingston is based and sampled from the Led Zep song "D'Yer Mak'er".
As blues being the foundation of rock, metal grew in the 80's during the birth of heavier sounding bands like Metallica, Slayer, Megadeth and Pantera. There, the sound evolved from the lighter rock and roll to the metal we know today as very, very savage. Here, where shredding comes to hand; a guitar playing style that includes fast playing of notes, sweep-picking, squealies and extreme use of a tremolo bar. Musicians that popularized this style include Eddie Van Halen in his guitar solo "Eruption". Later musicians that use this style are John Petrucci, Steve Vai and the recent star from Michael Jackson's "This Is It"—Orianthi. Metal drummers made use of double-bass pedaling to increase the speed of playing, while vocalists transitioned from the operatic and melodic style of Iron Maiden to a rougher, semi-monotonous style like Phil Anselmo's. Today, we have a variety of artists and sub-genres of metal; artists include Slipknot, Lamb of God, Mudvayne; here in the Philippines we have Wolfgang, Queso, Slapshock and Greyhoundz.
Mosh Pit. Typical scene in UP Fair. Man-to-man action with the JJ
Now, enough with the lecture and on to the point. We must not disregard this type of music even with its horned exterior; still it is a matter of choice. According to the song "The Metal" by Tenacious D, many types of music tried to kill the metal; including Punk, New Wave, Grunge and Techno. As I have said, I have no aversions on popular genres, and I also listen to them. Pop has delivered a very accessible kind of sound that everyone, even if some would say that they are die-hard metalheads, can't deny that they somehow like it. The thing is, metal has been treated like pigs by the mainstream, or to appeal with a growing number of metal fans, the corporate has been trying to prototype mainstream metal (includes Avenged Sevenfold and Linkin Park. They are good, but they sound too overly produced for me).
The problem with pop, moreover the companies that run it, is that they steal the genuine musical talents and turn them in to sell-outs by succumbing to music producers and pre-hand songwriters. The entire system of pop music has been reliant on what would sell, contrary to the main art of music that is expression. The standard today is that when you look good, you can be a singer. And what does that make here in the Philippines when you are a good-looking singer? A primetime telenovela/cheesy crap plot movie actor. We can't also say that pop is purely original music, look for the Sean Kingston reference above.
The Metal will always be here, and it's here to stay for good. And all you pop fans can suck on that.