While my archive site is down, I thought I'd share my thoughts on barre chords. Some call them, "bar chords." Either is correct, but I like to spell it, "barre" so as not to confuse it with the other musical "bar," which means a measure of written music.
Learning barre chords will increase your choice of keys available, increase the range of notes available in any given chord, make it easier to learn new chords, and allow faster and easier chord changes. Barre chords can even be easier to play than their "regular" equivalents. Really. Let's take these advantages one at a time.
CHOICE OF KEYS:
Each key is based on the first note of the scale in that key. The key of A major is based on the scale that begins with the note A. Within each key, there's a group of "basic" chords that are the most commonly played. In the key of G, these are G, C, D7, and Em, all easy to play. The trouble is, there are some chords that just can't be played without using a barre, such as F#m. If you transpose the basic chords for G into the key of A, you have to play A, D, E7, and F#m, so you wouldn't be able to play most music written in that key. Eliminating all the keys that require the use of barre chords (just for the "basic four") eliminates about 75% of all keys. Or, in a more positive light, learn to play barre chords, and you can quadruple your repertoire.
If you play an F chord the "normal" way, you can only play the first four strings, but if you play it as an E chord, barred at the first fret, you can play the low F on the bass E string, thus adding an entire octave to the notes available while playing F. But that's not all. You can also play F by playing a C chord-shape, barred at the fifth fret. This allows you to reach notes five frets higher than you could do while playing a "normal" F. Learning barre chords allows you to increase your range in both the bass and the treble.
LEARNING NEW CHORDS:
If you barre an E chord-shape in the first space, it becomes an F. Barre it in the third space, and it's a G, etc. For every new barre chord you learn, you are actually learning twelve or more different chords, depending on where you put the barre on the guitar neck. Barre chords are just the same, simple chords you already know, such as E, Em, A, Am, C, etc., played with a barre. You probably already know how to play Am, Dm, and E7, the most important chords in the key of Am. By barring them, you can play the same three chords at a different fret, and you've learned a whole new key! But it gets even better, 'cause you can play that key at any of the twelve frets, so by learning one group of three chords, you've added twelve entire keys to your repertoire.
LIGHTNING CHORD CHANGES:
With barre chords, the ONLY difference between an F, a G, an A, a Bb, etc. is which fret is barred. This means you can change chords just by sliding the left hand up and down the neck, which is much faster and easier than actually changing finger positions. Or you can switch back and forth between the barred E-shape and the barred Am-shape, while sliding your hand up or down the neck of the guitar one fret at a time. This is exactly what Bob Dylan did in "Lay Lady, Lay", beginning at the fifth fret with a barred E-shape, then the fourth fret with a barred Am-shape, then a barred E-shape again in the third fret, then a barred Am again in the second fret, creating a chord progression of unsurpassed beauty (A-C#m-G-Bm) without working up a sweat.
EASIER TO PLAY?
That's right! Once you learn to barre all six strings with the index finger, that part of all barre chords is the same. Always. But as you play further and further up the neck, the frets get closer together. Some chords that require you to stretch when played normally, are lots easier to play when playing in higher positions. Want proof? Play a normal C chord, then put a capo at the fourth or fifth fret and play the same chord. Which is easier?
SO, WHAT'S THE TRICK?
PRACTICE! You didn't learn the chords you already know all at once. You had to practice. But little by little, you got better, until it became easy. Persevere. If Django Reinhardt, who invented modern jazz guitar technique, could still play after losing three of the fingers on his left hand, you can learn to play barre chords.