The short history of the guitar

Much has been said about guitar history, and all the stars that bedeck it. What I find unfortunate, is that most guitar histories are blind to the greater context.
The guitar is a very young instrument. It has existed in its modern form -with 6 strings, and what is now standard tuning- only since the 1800s. It has been taught in conservatoires only since the 1960s.
Yet it is perhaps the most widely played instrument in the world today!
The fact is that serious study around the guitar has only recently begun. When compared to instruments like the piano (and its predecessors), or the violin (and its family), the guitar is in its baby shoes.
Yet its portability, availability, and relatively low price have made the guitar the instrument of the masses. It has become the symbol of  Rock Music.
And -don't get me wrong- I love rock music and rock guitar, with its irreverent mood, and all of what goes with it. But seen from a musical stand point, the music is usually pretty unsophisticated.
Not that it has to be, either! What I'm trying to point out is the larger picture here:
The lack of proper training schemes, and the exponential proliferation of the guitar mean that it is not only the most widely used instrument in the world today, but also the worst played.
The world of classical guitar, due to individualism, the lack of significant repertoire, and the lack of chamber music within that repertoire, has turned into a ghetto. A ghetto with very little contact with the broader world of music, and musicians.
To my mind, this means that although it would seem like we are living the age of the guitar, what we are actually seeing is a period of stagnation. The status-quo of music making on the guitar is rarely, if ever, questioned.
By this I mean the way the guitarist interacts with, and understands music, through his instrument. Beyond very simple patterns, the guitar is often lived more as an obstacle than an aid in this respect.
And if what matters most is the iconic image of the rock star holding his strat -with his godly status- then music making on a guitar is not likely to evolve much further down that road!

Rock guitar has defined its genre to such an extent that we tend to take it for granted: since rock music was born, the guitar has played a central role in it. But what are the roots of rock, and why is the guitar the emblematic symbol of this music?
Part of the answer lies in that it is such a readily accessible instrument, and rock and the genres that shaped it were certainly not the music of the elites. But let's take a closer look at the history of the guitar in 20th century popular music.

The origins: the Blues

BLUES is the result of a mixture of styles that, seemingly, have very little to do with one another. Yet, each of these types of music played a crucial role in determining the characteristics of rock.
In the first place, there was the traditional music that Africans from Mali and other regions, taken as slaves to America, brought along with them. Pentatonic scales, swinging polyrhythmic structures, and improvisation are three key aspects of that music. This style blended with the European traditions that the whites sought to impose on them: many African slaves received musical training at church. European religious choir music contributed harmony -as it understood in Europe- to the Blues and its liturgical counterpart, Gospel. Last, but not least, the proximity of the southern states of the U.S. to Mexico meant that African slaves were in close contact with Mexican rancheras, style which the main instrument of is the guitar.
This blend, together with an irreverent, "got nothin' to lose" mood, determined the characteristics of the earliest styles of blues.Country and Rockabilly
The blues had tremendous influence on all ensuing popular styles of music in America. Country and Rockabilly, the direct forerunners of Rock 'n' Roll, were no exception. White people started playing their own versions of the blues, blended in with other traditions of European origin: they tended to eliminate the polyrhythmic aspect -so natural to African peoples- and to focus far more on melody.
Other styles, like Ragtime and Jazz, retained the African elements to a greater degree, and in some cases even returned to them in a very conscious way (As Hardbop did, for instance). However, the guitar played a minimal role in Jazz up until the 1960s, and even since then, it has only been one of many instruments used in that musical genre, too.
Folk and Rockabilly, however, adopted the guitar as their main instrument right away.

Country and Rockabilly

The blues had tremendous influence on all ensuing popular styles of music in America. Country and Rockabilly, the direct forerunners of Rock 'n' Roll, were no exception. White people started playing their own versions of the blues, blended in with other traditions of European origin: they tended to eliminate the polyrhythmic aspect -so natural to African peoples- and to focus far more on melody.
Other styles, like Ragtime and Jazz, retained the African elements to a greater degree, and in some cases even returned to them in a very conscious way (As Hardbop did, for instance). However, the guitar played a minimal role in Jazz up until the 1960s, and even since then, it has only been one of many instruments used in that musical genre, too.
Folk and Rockabilly, however, adopted the guitar as their main instrument right away.

Rock 'n' Roll and Beyond

In contrast to Jazz of the big-band era, where the guitar was used mainly in the rhythmic section, Rockabilly and Rock 'n' Roll kept using the guitar more as it was used in traditional blues. In commercial records of that time, though, the emphasis was more on vocals than on instrumental solos. Nevertheless, the guitar was close the foreground all the time.
The big revolution that turned the guitar into the solo instrument it is in rock nowadays happened in England. Bands like the Yardbirds, John Mayall and the Bluesbrakers, and many others, influenced as much by the harsher sounding blues music, as by the more commercial Rock 'n' Roll records of the time, started using the guitar as a lead instrument more prominently: this way, modern rock was born. Jeff Beck, Eric Clapton, and Jimmy Page were all the lead guitarist of the Yardbirds at different points, and each would later have a huge impact on the development of Rock Guitar.
Jimi Hendrix, also drawing heavily on the blues tradition, and greatly influenced by psychedelic rock from Britain and other styles such as funk, had as big an impact (if not greater) on the development of rock guitar as his British counterparts.
The way the guitar is used in rock was forever changed by these revolutionary guitarists.