A popular IFB pastor in Michigan said, "unplug the instruments and Contemporary music goes away." Eventually the 9 volt battery in his wireless mic died.
I am all for the creative use of sound. I once played the rear brake drum from a car during a classical piece.
Anything that enhances the music is fine for worship.
Sometimes its a good idea to "unplug" a few things and get down to basics but this pertains everywhere with music. This is why the "MTV Unplugged" concerts were so popular.
Just yesterday I was telling my pastor that I'd like to (at times) strip things down to a couple of instruments (acoustic guitar, keyboard, put the drummer on a "cajon," Etc.). My rationale is threefold:
1. The focus is more upon the message of the songs which the congregation should be meditating upon and considering.
2. Practice time is very limited and is quite chaotic. Only on Saturdays for a couple hours with many other things going on and people demanding use of the auditorium. If I limit it to another guitar player and someone on a cajon, we can practice anywhere with far greater flexibility.
3. At this time, the skillset of many of our worship group volunteers is very limited so not only are you teaching them the songs, you also have to teach them how to play their instrument! Most of the singers also do not know how to harmonize so having them up on the platform actually detracts from what we are doing. Therefore, I could hand-pick one or two in our congregation who actually have some musical "chops" and do something cohesive!
We usually have three songs so I'd like to explore a "Psalm, Hymn, and Spiritual Song" concept where we do either a "Scripture Song" or something adapted from an old Psalter, a REAL Hymn (not just the sappy, sentimental stuff that creeps into hymnals these days), and a Spiritual Song that may be "contemporary" in nature but substantive and doctrinally sound.