Why are guitar strings tuned as E,B,G,D,A,E (bottom->top)?

Historical Roots:

The modern guitar's tuning system has its roots in the ancient Greeks and Romans, who used a similar tuning system for their lyres and kitharas. The Greek philosopher Pythagoras is credited with discovering the mathematical relationships between notes and frequencies, which led to the development of the harmonic series.

The Harmonic Series:

The harmonic series is a fundamental concept in music theory, where a string's frequency is divided into integer ratios to produce harmonious notes. The harmonic series is the basis for many musical scales and tunings, including the standard guitar tuning.

Why EADGBE?

So, why did the standard guitar tuning end up as EADGBE? There are a few reasons:

Historical influence:The guitar's tuning system was influenced by the lute, a popular instrument in the Renaissance era. The lute's tuning was based on the harmonic series, and the guitar's tuning evolved from this foundation.
Instrument design:The guitar's design, with its fretted neck and six strings, lends itself to the EADGBE tuning. The tuning allows for a range of notes and chords to be played comfortably, while also providing a good balance between the low and high ends of the instrument.
Musical practicality:The EADGBE tuning provides a practical range of notes for many styles of music, from classical to rock and pop. It allows for easy chord shapes and scales, making it accessible to players of all levels.
Convention and tradition: The EADGBE tuning has been the standard for so long that it's become an ingrained part of guitar culture. Many guitarists learn to play in this tuning, and it's widely used in music education and instruction.

Alternative Tunings:

While EADGBE is the standard, there are many alternative tunings used in various styles of music. Some examples include:

Drop D: DADGBE, commonly used in heavy metal and hard rock music.
Open D: DADF#AD, used in blues and folk music.
Open G: DGDGBD, used in blues and folk music.
E flat: EbAbDbGbBbEb, used in heavy metal and hard rock music.

These alternative tunings offer different sonic possibilities and can be used to create unique sounds and styles.

In conclusion, the standard guitar tuning of EADGBE is a result of a combination of historical, instrumental, and musical factors. While there are many alternative tunings available, the EADGBE tuning remains the most widely used and accepted standard in the guitar world.