question

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With a chord like this (this one being the first chord of GNR's Knockin on Heavens Door") am I supposed to mute the A string, or just pick those? It always seemed convenient to just mute it and strum but I have a feeling thats probably wrong.

you can do that. thats how i would go about playing this G chord. or you might as well go for it and put a 2 on that A sting. noone will really notice.

You played it right.....just mute the A string and strum the rest....

I would just mute the A unless it specifically says somewhere to fingerpick it, or if the chords before or after are finger picked.