Adding 4ths and 6ths to One finger barre chords

good question. maybe this site can help.
http://www.acousticfingerstyle.com/OpenG/OpenGFrames.htm

First, you identify the chord tones from the tuning. That's going to differ with the exact tuning you use, so let's say your open D is this:

D-A-D-F#-A-D

Those tones are 1-5-1-3-5-1

The fourth is one fret higher than the 3rd. So if you want to do an Esus chord, you'd do this:

2-2-2-3-2-2

which raises your 3rd to the 4th

If you want a 6th chord, you raise a 5th by two frets, so for E6 you could play:

2-4-2-2-2-2

or

2-2-2-2-4-2

Simple rule of thumb I've always used....

in open G, put the barre chord on then add an Am7 shape to add the 4th and the 6th. the second string will be the fourth; the fourth string will be the 6th.

...G.. Gsus4..G6..G7..Gsus4/9..Gadd9

D 0......0......0....0.....0.........0
B 0......1......0....0.....1.........0
G 0......0......0....0.....2.........2
D 0......0......2....3.....0.........0
G 0......0......0....0.....0.........0
D 0......0......0....0.....0.........0

in open D tuning simply move those chords one string down towards the bottom E string (which will be D, in open D tuning) and think an E7 shape instead of Am7.....

D.........0 0 0 0 0 0
Dsus4....0 0 1 0 0 0
D6........0 0 0 0 2 0
D7........0 0 0 0 3 0
Dsus4/6..0 0 1 0 2 0
Dsus4/9..0 0 1 2 0 0
Dadd9....0 0 0 2 0 0

The great thing about those chords, it's incredibly easy to play a 12-bar blues/boogie riff using one or two fingers....try G, G6, G7, G6 and G. or D, D6, D7, D6, D.....no need to stretch that pinky 5 frets when you can do it in three!

:D :D :D

Vic

Thanks everyone for your replies.Lots of help.

Cheers
Bruce