Or, Excellence in Worship Music
Here's an issue that spans every style and preference of worship practices: the quality of the music sung/played during worship.
Whether you have a cantor, a choir, an organist, a pianist, a keyboard player, drummers, ensembles...you name it, or if it's the congregation together singing unaccompanied, how well music is presented is important.
I don't mean that we must all be expertly trained professional musicians. However, I believe God deserves the best we can give.
I believe we human beings probably cringe more than God does. After all, even the glorious sounds of a Cecilia Bartoli or Yo Yo Ma must sound like the tiniest, most amateurish efforts to the One who invented music and created our various gifts in making music. However, I suspect that the Almighty is saddened far more often than we are when we sing or play in a lackadaisical or careless manner. What a waste, and for such an Auditor!
I also don't mean that any one type of music is superior to any other type. There is nothing more intrinsically holy about a baroque organ cantata or plainchant than a Southern Gospel song or edgy rock-style piece, so long as the text (if any) is a genuine expression of the faith we profess and is sung/played with the intention of worshiping God.
I only mean, for heaven's sake (and I mean that literally), let our music be presented with excellence!