I didn't hear the drums, horns or harps. That said, I enjoyed the video.
I have to ask. The Psalm mentions several things to do.
It says to sing aloud.
It days to beat the drums (hand drums....kinda like tambourines).
It says to use a harp.
Ir says to blow horns.
Why did you select "sing aloud" and ignore the rest of the Psalm?
The video that you saw was only one of the songs that we sang in worship on that evening. That service was many years ago, but I am confident that in some of the other songs we did use some of those other instruments.
We do have people playing harps, horns, and some percussion instruments regularly in our services, but you will never hear any music in my church where the use of percussion is anything like what characterizes CCM/CWM.
In addition, I am not ignoring the rest of the Psalm. When you carefully and thoroughly compare Scripture with Scripture, it's clear that what Psalm 81 teaches has to be harmonized with other passages. Those passages shows that God has accepted corporate worship that did not always feature the use of all the same combinations of instruments played at the same time.
For example, 2 Chronicles 5 records one of the most important occasions of corporate worship in the history of the world-- at the dedication of the Solomonic Temple. The biblical record of that event speaks of the use of cymbals, psalteries, harps, and trumpets (2 Chron. 5:12-14) but does not say anything about the use of timbrels, tabrets, or any other kinds of drum-like instruments.
We know with absolute certainty that God accepted that corporate worship that does not mention the use of any drum-like instruments.