Barring D and A major

I say any way you want to form a chord is fine as long as it doesn't change the sound, but that's a bigger catch than you might think. You have to remember that there are usually good reasons why the common ways to do it became common in the first place. Ease/speed of change to other chords - as you mention for D7 - is one.

Also, tell your friend that even though he may not be able to hear the difference between muting the high E and not muting it - others can (in fact, the highest note of a chord is often the most important note), and he will be able to in time too. When he gets to that point, he's going to be mightily annoyed with himself if he's already taught himself the 'wrong' way to play A. (I speak from experience, I'm currently wasting hours of good learning time retraining myself to play barred A-shapes without muting either the high E string or the B, and I cringe when I get it wrong.)

I definitely agree C&S. Muting the high E on Amaj takes something away from the 'happy' sound all major chords have (or should have).

But you'll also find that guitarists often do mute the high e on the A. It's not at all unusual. I do it myself frequently (especially in rock songs and on electric) though not always. And you'd also have to consider that if you play the A in other places on the neck (the E shaped barre on the fifth fret, for example, has an A as the highest note or the D shaped A at the ninth fret has the C# as the highest note) the E isn't always the highest note. In fact, I suppose muting the high e and having the C# or third as the highest note is much like playing the A at the ninth fret where the C# is also the highest note. There's no rule that says that the E must be the highest note in the chord.

What Musenfreund said. It seems to be a pretty common thought among guitarists that chords have 'good' voicings and 'bad' voicings, which is total nonsense. The top note's main function is to support the melody, so whether that top note should be an E, C# or A in an A-major chord totally depends on what the rest of the instruments is doing. One should be able to play every inversion of every chord and use them to their best effect. So you should be able to play the A-shape barre both with and without the high-E.

Just mt two cents. :)

Yeah, good catch guys - I didn't explain it very well. I'm not saying you must play it, just that ideally you want to be able to when the song warrants it. Just deciding now that you'll never need it because you can't hear the difference (or you think others can't) is a little short-sighted.

Muting the high E on an A is simple enough...if that note isn't crucial to the song or the song sounds better without it, by all means mute it. My only thing is that I don't want to develope bad habits. It sounds like both ways have their uses, though. I guess barring A can't really be considered a bad habit anymore though...what do you think of barring the D chord?

Sorry, I don't get the question. What do you mean with barring the D-chord, and what is potentially wrong about it?

Arjen, I mean playing the high e and g strings with your index on the 2nd fret, and playing the B string on the 3rd fret with your ring (or middle) finger. I think going from a 'barred D' to a D7 would be an issue.

Nirvgas,
Think about it this way: the A at the second fret is the 0-position barre chord. If you move everything up one fret, you'll play a Bb (or A#). But now you have to barre the first fret. Barre chords are a way of creating a moveable "nut" with your finger. Move up two frets and you'll play a B. Three frets a C. Four frets a C#; five frets a D. Everything we've all written about the A chord at the second fret holds holds for each of these chords.

Now, when playing the D7 at the fifth fret, you'll not have to worry at all about muting the high E string because you can use your ring finger and little finger to grab the second string at the 7th fret and the fourth string at the 7th fret while barring the others at the fifth fret. The high e is a bit of a non-issue for the 7 chords played with a fifth string root.

I hope that makes sense to you.

Arjen, I mean playing the high e and g strings with your index on the 2nd fret, and playing the B string on the 3rd fret with your ring (or middle) finger. I think going from a 'barred D' to a D7 would be an issue.

I think he's talking about a three string bar of the usual open D.

It is hard to switch between D and D7 this way. But it's easier to switch to other chords this way. For example, the chord progression in Simon and Garfunkle's "America" goes D Dmaj7, Bm, D, G, D.

If you stick to the lower three strings, and use a barred D, then swtiching from D to Dmaj7 means just lifing your second finger. Otherwise, it's a major pain to hit. You can then do the Bm simply by putting your second finger back down, and your ring into place on the third string. Then at G time just move your barre finger down three strings. Then switch it back up to D. You've just played a non-trivial chord progression with an incredible economy of motion, with interesting voicings to boot.

Do what the song calls for, in a way that sounds good. Being able to finger a chord several different ways will allow you to easily play songs that seem impossible to someone intent on doing it the "right" way.

I have to admit though that I'd play the open D, D7, and Dmaj7 shapes for that song. It's the most efficient fingering, I think. I wouldn't bother with a barre there at all.