John,

Here's an interesting anecdote for you.

[anecdote]

Most non-guitarists realize that a single note can be played in several different positions on the neck.

What most non-guitarists don't realize (actually, most guitarists probably don't realize it either) is that each position has a significant difference in timbre, which is basically due to the thickness of each string being different, and the length of the string changing when the same note is played on different strings. This alters the harmonic content of the sound.

This is why guitarists have an extra layer of emotion that they can add onto their playing, if they care to explore it. You can play one phrase in one position on the guitar and it will sound a certain way. You can then move that phrase to a different position but play the exact same notes, rhythm, expression, etc... and you will get something that sounds totally different. ...at least to my ears.

That's why being able to play any note / scale / chord in any position on the guitar is important. It opens up a world of sonic and emotional possibilities.

An extension of this is seen in some styles of "flatpicking", where the same note is played over and over in rapid succession, but on alternating strings. A non-guitarist would look at the sheet music for this and just see the same note in rapid succession... Boring! However, if the guitarist plays alternating notes on alternating strings, the tonal qualities of the sound will change, even though the pitch is exactly the same. Listening to that kind of playing... even a non-guitarist can tell that something cool is happening!

It's kind of like if you sat a tuba and a trombone next to each other and played alternating eighth notes back and forth between the instruments.

[/anecdote]