So, I'm listening to a Google Hangout with worship leaders talking about music and hymnody, and they're saying:
1) Worship on Sunday is an active continuation of worship throughout the week. (It isn't just one day)
2) A congregation is not an audience. The only audience is God. (We are not passively listening)
3) Songs help us to mediatate on truths, so lyrics do matter. Take, for instance, the hymn "Psalm 90" by Isaac Watts (I, Joseph, slightly modernized some words, such as "Thine" and "Thee"):
Our God, our help in ages past,
Our hope for years to come,
Our shelter from the stormy blast,
And our eternal home.
Under the shadow of Your throne
Your saints have dwelt secure;
Sufficient is Your arm alone,
And our defense is sure.
Before the hills in order stood,
Or earth received her frame,
From everlasting You are God,
To endless years the same.
Your word commands our flesh to dust,
“Return, you sons of men:”
All nations rose from earth at first,
And turn to earth again.
A thousand ages in thy sight
Are like an evening gone;
Short as the watch that ends the night
Before the rising sun.
Our God, our help in ages past,
Our hope for years to come,
Be Lord our guard while troubles last,
And our eternal home.
4) With that said, theological lyrics are not the only thing that matters; melody and music matter a lot. They point to beauty, and that points upward.
5) A lot of this is counter-cultural to emphasize truth