I have thought a lot about this over the past couple of days. And after our first Easter rehearsal maybe I can add a little light to the frustration of the congregation. When we sing a new song, or even an old and much cherished hymn, we first sing it in a specific arrangement, a specific key, with specific harmonies, if we are fortunate enough to have harmony in the song. We sing that arrangement several times over the next few weeks. Often times when we go back to that song weeks or even months later, something has changed to make it almost impossible to sing what we sang the first few times we sang it. The key is changed, it is higher and some people can't sing that high, or it is lower. The chord structure is changed to make it more interesting, so the harmonies learned no longer apply. It is faster, or slower or there is a bridge that has been added and the congregation, in their frustration of trying to sing a familiar song shuts up because they are trying to sing what they know, not what is being played. So, in our attempt to make music more interesting, maybe we are hindering the worship by changing too many things in any given song.
You have to remember, every time you change a song, you practice it several times until it becomes more familiar to you, the congregation gets one shot at it. Goodness, even the choir, who gets three shots at it, may finally feel comfortable with a new arrangement in the last service, and that is after at least two rehearsals. Jboats

Excellent point jboats! This is where my comments fall short. It is the responsiblity of the worship leader / worship planner that we make songs accessible to our congregation. This means the keys, arrangements, and accompaniment contribute to a positive participational experience. Certainly we all fail at this at times, especially since the very nature of the artist is to want to create new things. We must remember that if our creativity is the reason people don't sing, then we have gone too far.