Guitar is an instrument that handles every single form of musical genre out there. Many, many people say that they are a "rock guitarist" or a "blues guitarist", yet very, very few say that they play "everything" or play it well.
When I first began guitar at age 8, I didn't listen to much music other than the Eagles and the like my dad played. My guitar teacher asked me what I liked and I told him I didn't know. He started me with early classics like Ray Otis' "Sittin on the Dock of the Bay", Eddie Floyd's "Knock on Wood", and similar songs. While I didn't take a particular interest in the music that I learned on guitar, my dad was listening to pop-rock such as Matchbox 20 and older stuff such as Paul McCartney's Wings.
I began to hear my older cousins (whom I took up music from in the first place) discuss older 70's rock such as led Zeppelin. Later that year, I heard Stairway to Heaven and bought Zeppelin's "IV" album. I fell in love with that album and listened to every song over and over again, eventually learning Stairway to Heaven, Black Dog, and Rock 'n' Roll on guitar. This sparked my interest in rock music. I began to pick up on 60's classics such as Hendrix's "Purple Haze" around this time as well.
After a couple of years of intense "rock guitar" studying with my same guitar teacher, he pulled out a lead-sheet of a jazz number that I believe might have been Miles Davis' "So What?" I put little interest into it, much to my teacher's dismay.
The same thing has happened with classical study (being baroque and romantic music) and alternative music (such as reggae and ska).
After several more years of procrastinating new music, I finally decided to pick up jazz and classical. Fuel by my cousins musical tastes (which, to this day, seem to be one step ahead of my own) I picked up jazz, ska, and funk.
What in the hell does this have to do with learning how to be a well rounded musician?
My prolonged story is similar to that of most teenagers playing guitar. They are interested in only rock and metal and refuse to listen or play anything different. On other ends of the spectrum, some guitarists will only play classical or ska.
Why doesn't anyone choose to play as many genres as they can?
My theory is because the feel insecure about their musical tastes and choose not to play outside the genre they listen to.
How can YOU, the reader, change this common mentality?
Step I: Identifying Music
While this may seem asinine and useless, this is actually critical to learning as many genres as one can on guitar.
Those genres are generally considered to be the essence of modern music.
Relating Those To Guitar
Research and explore the music above. Find 3 artists in each genre you like and learn an album. It's really that simple.
For instance: in Rock and Roll, I would say that Led Zeppelin, Guns n Roses, and Pink Floyd are my 3 favorite artists of classic rock. I have learned the entire IV album for Zep, all of Appetite for GNR, and all of the Wall for Pink Floyd. I can say that I have distinct aspects of blues-inspired rock in my soloing from learning those albums.
Relate the same to other genres. It takes lots of time, but it's great to record your progress and play it back after a few months to notice the change in your style.
Never, ever, ever, ever, EVER decline an opportunity to play with other musicians. Be it a garage-style jam or an invitation to play as the guitarist for a jazz ensemble. I have even played trumpet in a jazz ensemble.
Be on the look out for local concerts. Don't just look for rock concerts either. I went to a gig sponsored by my city's art-board that featured a classical guitarist and Irish fiddler. I was impressed by the style and even wrote a song inspired by it.
Learn your scales in all 5 positions. (For movable ones) Practice to perfection. This means major, minor, and all modes and pentatonics.
Always practice your site-reading. This is crucial especially to those of us hoping to study music in college. It's boring and challenging, but it mentally maps scale degrees and scale boxes.
Be open minded. It's safe to say that I don't like country. But there have been several songs that have perked my interest because I listened to it with an open mind. There's nothing better than finding a new gem in music.
My math teacher played folk all the time when we were doing independent work and tests. One time, he played a song that I instantly loved by an artist named Bon Iver.
After buying his album and EP, he has become one of my favorite musicians, and I'm not even a folk fan.
That's about all I can think about, thanks for reading and please rate critically and leave constructive comments. Thanks