Phrasing, Dynamics, Rhythm, Technique and Tone. The 5 big components that make up a great musician. Notice I said, musician and not a guitarist. The concept of being a quote on quote "guitarist", is something very different from being a true musician. A musician uses his or her instrument as a vehicle of expression. The intent of making music and clearly stating musical ideas is of the utmost importance to a musician. A guitarist on the other hand may or may not fully understand basic concepts of expression. Some Guitarists identify themselves via their instrument and do not realize that it is their own musical ability which generates artistry. Development of musical rudiments is often ignored in favor of learning riffs, reading tablature and haphazardly learning technique. Perhaps the most crucial exemption a guitarist makes is failing to develop a good sense of rhythm. Lacking all of these tools hampers advancement and musical development. Most importantly music itself suffers, breeding mediocrity.
How then does a guitarist bridge the gap? Most importantly what is the gap? First of all, a guitarist must understand that it is the person who makes the music, not the guitar. The guitar is merely an object with strings that on its own has no musical ability whatsoever. The gap is all that musical knowledge that we do not have. All the musical deficiencies a person has will never go away unless we actively seek to fix our musical flaws. Bridging the Gap can only occur once you actually begin building a bridge upon which to fill the gap. There is no end to the bridge, there is no ending to your musical development. That's the beauty of being a musician.
Also, when asked what I play, I tend to answer, "I play classical guitar, you know, classical music...first and foremost though I'm a musician".
Music making is a craft, a skill, a talent, what we use to bring music to an audience is a variable left to those skilled enough to excel at it.