The strings of the guitar are tuned to six particular musical notes: E, A, D, G, B, and another E. When properly in tune, these notes will be the same exact tones that any other musical instrument would play, be it a piano, a bass, a flute, or violin.

This is what makes it possible for all different kinds of musicians to make music together, and have it all blend beautifully. Tuning your guitar every time you play is essential to training your ear to recognize and become familiar with the way the notes of the guitar should optimally sound.

If you skimp on the tuning, you shortchange yourself. Even the most fantastically advanced piece of music, if played on an out-of-tune guitar, is going to sound pretty bad.