This gives me an idea. What if a church allowed people to quietly nod their head to the song that was coming through a personal set of ear-buds or headphones? It would be Similar to the airlines that have a limited radio station list on airplanes, only it would be different song Christian genres, songs, but same message-- so the pastor's sermon can correlate with each listener. This unique devices would have noise cancelling capability so that people's "songs" do not interrupt the message through music. Also, these devices would be jammed, as would cellphones, once sermon time approaches. Oh, there would be live music, too. Only, the genre and song would be chosen from the day's list via a manual BINGO # scrambling basket thing-uh-muh-jig-- each service.
As for loudness during the live worship with music portion, this would vary, BUT, each church attendee/participant would be able to use the noise cancel ear pieces, or move to the sound-proof all-transparent, plexiglass room in the back. Basically, the higher you jump or run. As for singing from the congregation, everyone would have a min mic built into a their headphones, so if someone wanted to sing they could be heard heard the the Group Genre Song Choice of the Day Channel (GGSCoDC for short). The GGSCoDC would be listened to by a Sound Control Technician, who could mute, or turn up or down the congregation through the headphones.
this is a work in progress, but while it may seem unnecessary... people would start to crave for the customizable personal-interest oriented corporate worship experience.
...kidding.