when playing chords like c & a how do you no when to strum all the strings or just a few?
because when you don't strum a string it is labelled with an X in tab. I think that is your question.
Some songs only use partial chords and a lot of the time in the chord listing they arenot listed properly ie it may tell you to play an A chord but in the actual song they may only be hitting the open A string and D string 2nd fret which I believe is basically just a power chord
with practice your ear will be able to pick out the minor diff in the two.
As Ryan said above, in the tab they should have it marked with an X if you are not supposed to hit the full chord.
pics of gear updated on profile 11/16/09
A lot of times when you're playing a chord in the context of a song, you're using a strumming pattern utilizing a series of down/up strokes. Let's a assume you're playing open G, which uses all 6 strings. You would strum all six going down, but mix up your up strokes with only strumming maybe the bottom four(starting from the high E). Doing it that way gives your playing a little more character.
Hey lee8040,
Try playing the chords you mentioned by taking away some of the strings. You will notice the change in character as notes are taken away, and according to your taste, if you're only given a sheet with chords, you may strum in whichever way you want. There are technical aspects, but you can give this method a whirl.