Food for thought from Renewing Worship blog:
Worship leaders around the world are sadly changing their church’s worship (often unintentionally) into a spectator event, and people are not singing any more.
Before discussing our present situation, let’s look back into history. Prior to the Reformation, worship was largely done for the people. The music was performed by professional musicians and sung in an unfamiliar language (Latin). The Reformation gave worship back to the people, including congregational singing which employed simple, attainable tunes with solid, scriptural lyrics in the language of the people. Worship once again became participatory.
The evolution of the printed hymnal brought with it an explosion of congregational singing and the church’s love for singing increased.
With the advent of new video technologies, churches began to project the lyrics of their songs on a screen, and the number of songs at a church’s disposal increased exponentially. 
At first, this advance in technology led to more powerful congregational singing, but soon, a shift in worship leadership began to move the congregation back to pre-Reformation pew potatoes (spectators).
What has occurred could be summed up as the re-professionalization of church music and the loss of a key goal of worship leading – enabling the people to sing their praises to God. Simply put, we are breeding a culture of spectators in our churches, changing what should be a participative worship environment to a concert event. Worship is moving to its pre-Reformation mess.
I see nine reasons congregations aren’t singing anymore: Continue reading
H/T Glenn Chatfield