If you’re in a ministry where you want to use orchestral instruments (or are required to) yet still want the feel of contemporary worship, here are a few ideas.
The arrangement must fit the style of the song. The brass and woodwinds shouldn’t dominate — otherwise you risk sounding like a high school band concert. Instead, allow your praise band to carry the arrangement and let the orchestral instruments provide color — a line here and there that can cut through the mix. Heavily orchestrated Camp Kirkland type arrangements are more suited to a First Baptist type church and muddy the mix in a praise band setting.
In my HymnCharts arrangements, I often double the strings with other instruments to add more punch to a melodic line. A violin by itself might not even be heard over a praise band, but doubling it with a flute or clarinet gives the line added strength. Modern worship is linear — I don’t want a bunch of intricate instrumental parts complicating the band groove.
The instruments themselves must fit the style of the song. In medium to smaller churches you run into the problem of a mishmash of random instruments. Don’t attempt to include wildly different instruments like a tuba and flute into your praise set. If possible, use instruments that complement each other — flute/violin, trumpet/clarinet, etc., and let the other instruments take a break that week (frankly, I don’t think I could ever find a place for a tuba on a Chris Tomlin song!)
In the olden days, orchestral instruments in church were a weekly feature. In our more contemporary, praise band driven world, orchestral players usually provide occasional sonic icing to the electrified sound.