1. It is so much easier to get a congregation to sing heartily if the song is driven by it's melody rather than by it's chord progression. For this reason, hymn-like songs just work better for congregational singing than rock songs.
2. Songleaders are the most important ingredient if you want the congregation to sing. Good song leading gives the congregation confidence and enthusiasm.
3. Vocal harmonies are delicious. Particularly a tenor line.
4. If I (a pianist) had to choose between a violin and a guitar, I'd take the violin. Guitar adds more complexity and, for a newby band, much more risk. I'd want bass and drums long before guitar.
5. It's easier to get a morning congregation singing heartily than an evening congregation.
All of this makes me sound really conservative. Perhaps I am. But more than ever before I am focussing on what helps the congregation sing out God's word. And it's old school stuff.
Here's our current song list:
When I Survey
How Great Thou Art
Great is Your Faithfulness
Be Thou My Vision
Come People of the Risen King
How Deep The Father's Love For Us
In Christ Alone
Let Your Kingdom Come*
Before The Throne Of God Above
Ten Thousand Reasons