Let´s start with the name - this is very simple. Rock and roll, like jazz, was a Negro (Black American English) term for sex, so in puritanical America, the music definitely had a transgressive edge.
Defining what rock is musically is relatively simple too. Obviously, the main ingredient is the electric guitar, but to be precise, it´s the riff-based sound created by overdriving the valve amp into saturation.
This overdriven guitar tone was achieved by turning the amp up full and letting the valves do their magic. By driving the poweramp section of the amp (turning it up loud) a great crunchy tone was produced – AC/DC, for example - though it usually deafened everyone in the room!
The guitar sound makes a musical statement. What that statement is, is debatable. For starters, power, rebellion, mass.
Rock music evolved from early players such as Chuck Berrry in the hands of 60s performers such as Jimi Hendrix, Cream, Deep Purple, Led Zeppelin and Black Sabbath. Guitarists like Eric Clapton discovered the beauty of driving a Marshall amp at full tilt. Each of these artists was a musical innovator, taking their musical influences from blues, classical and jazz and inventing their own, unique sound.
Some early musical experiments were unsuccessful, however. Take the Kinks, for example, who tore their speakers to make them distort, resulting, not in harmonic overdrive, but uneven, harsh distortion.
The bands mentioned above created the template for what became Hard Rock in the 1970s, as some guitarists began driving their amps harder by using an overdrive pedal through their already overdriven valve (tube) amp. The music became more powerful, even more riff-orientated and the riffs more repetitive.
As I discovered reading British music papers like The New Musical Express and Sounds NME, the best rock bands were Journey, Kiss, Boston, Utopia, Angel, Rush, Rainbow, Van Halen, UFO, Styx, Starz, Angel, Whitesnake, Alice Cooper, Scorpions, Boston, Thin Lizzy, The Babys, Aerosmith, Montrose, Mott The Hoople, Foreigner, Rush, Sweet, building on the music of Ted Nugent, Free, Bad Company, Judas Priest.
In fact, NME covered the KISS 1980 British tour and crowned them the Kings of Rock.
Then Hard Rock mutated again. By the late 1970s, amp manufacturers realized that guitarists wanted a more overdriven / distorted tone and began to add more valves in the preamp section of the amp causing it to distort more at lower volumes.
The result was an unpleasant, fuzzy tone which became the sound of Heavy Metal. This fuzzy preamp distortion severely limits how the guitar responds to the player´s touch (though it can give single notes a singing, sustaining quality). Using dissonant, disjointed figures and chordal movements added to dropped tunings and double bass drum patterns, all played to the extreme with screeching vocals, the music began the decline into the aggressive, mechanical banging of today´s thrash, death and black metal.
These “genres” that lack the harmonically rich poweramp overdrive, musical substance, ebb and flow, feel, soul, or rock or roll, aren´t rock and roll.
And in my opinion, they aren´t music!
What do you think?