On the first song my 'b' string seemed to be a bit out of tune, so I re-tuned it and went on my way. But after each song it was more and more out of tune. I tried to play only low strings or adjust the fret or two during the song, but mostly it just sounded terrible. By the next to last song my 'b' string was dropping a minor third (down to G# or as bad as it could possibly make my guitar sound) after just a few strums. One of the women helping sing that morning stepped up to the mic and said something to the effect of it being good that God hears the praise of our heart, out of tune guitars and all.
After finishing, I went and removed the string and put it right back on. Problem solved (although I still don't know how the first time I put the string on things went so badly). Just a good reminder of what is important as I lead worship times and youth group things. Our hearts have to be offering all of ourselves to God.