I understand that you mean to defend your idea that instrumental music in worship somehow changes the worship. I don't really understand how singing along with instruments changes the singing, when teaching through a computer doesn't change the teaching. They seem to be perfectly analogous concepts to me.
Yes, I know they look different to you, because it's your tradition. I can't make a dent in that, so I won't bother trying. Perhaps one day you'll see what I mean. In the meantime, have a nice life.
Mechanical instruments of music are not a medium through which singing is done. They are a separate type of music. Using a computer to spread the Gospel is only a medium through which the teaching is done. If "speaking to yourselves" and "teaching and admonishing one another" could be done by mechanical instruments of music, then they would be an expedient. However, that is not the case. They are an addition.