I'm pretty new to the banjo, mostly working on learning to play the chords to back up my singing. So far, whenever I try to play a song outside of the key of C, it doesn't sound right. For example, I've been working on this song: http://www.martindardis.com/garden_song_lyrics_chords.html
So, when I tried to play it in the key written, it sounded completely wrong. (I followed the chord chart given here: http://www.tommyjordan.com/chords.htm in an open G tuning) When I converted the chords to playing in the key of G (with the same tuning), it sounded much better. Every song I've tried in a key that wasn't G sounded off; almost all the time I've moved it to G it sounds better (with I IV V chords sounding right always; the other chords in a song sometimes sounding right but not always). Why is this? Why can't I just look up the chords on a chart and they sound right?