Yesterday I offered a few thoughts on the relationship between the message and musical element of the service. Here are some more thoughts:
Whiplash can be painful. My friend Ron speaks of the whiplash effect in some church services. The singing is filled with emotive love of God content, then the sermon harshly snaps listeners back to the other extreme with a brutal blend of duty and pressure. From delight to duty, from presence to pressure. We do not cover the full spectrum of Christianity with this whiplash blend, we contradict ourselves.
Songs don’t have to tie in completely, but they shouldn’t be radically out of place either. Sometimes I’ll select a song that complements the message by majoring on a fact that is not central, or even present, in the message. The complete package of the service can do a work in peoples’ lives, it doesn’t just have to be a preview of the preaching.
Song leaders should be careful not to give away tensions in the sermon. An overzealous leader can sometimes give away aspects of a coming message that would be better left for the preacher to communicate at the right time. A good relationship between preacher and song leader (pick your own title of preference), is worth its weight in gold in that respect.
(While mentioning song leaders, think through introductions of speakers too.) Too often the transition from song leader to speaker is undermined by excessive introductory comments (sometimes bordering on idolatry in some circles), or by lack of sensitivity from the speaker. Sometimes that great compelling and captivating opening silly salvo simply doesn’t fit and the speaker would do well to pause, to pray, to reflect further on what has been going on. Sensitivity both ways really matters.
What else could be added . . . more, I’m sure. Remember that to be committed to the Word and to expository preaching does not mean we have to therefore disparage the musical elements of church life. Both are very important. Thought put in will usually bear fruit.
Biblical Preaching 
Some thoughts. Coordination of praise time and sermon time is useful, although often lost on the congregation. For me, the bulk of the praise time should be familiar music which elicits maximum, heartfelt participation. Only one or so selections should be aimed specifically at the sermon.
In this sense, the praise serves the fellowship’s need to lift up voice to the Lord, not to be an adornment to the sermon-of-the-day.
Next, if there is to be a “song of celebration”, let it be celebratory! Often, pastors think that because a song contains the word “joy” it must be celebratory. Often, they are wrong because many pastors are music-dumb. Let the worship leader choose the praise music so you can concentrate on the sermon message.
Lastly, we live in a music saturated society. Add to the praise time and encourage liveliness. This elevates the congregation and increases their anticipation of your message. Dull praise prepares the body for a dull message.