The songs that everyone knows the best can be the worst.
Wait… What? If everyone knows them that well, how can that possibly be bad? Because what happens is that they know them SO WELL, they may not prepare them. Or they know them SO WELL that they are completely “checked out” during worship and miss a cue to repeat a verse. Or they know them SO WELL that they miss the part they’ve been singing wrong for years. Or they know them SO WELL that when they play the song for the congregation, IT IS COMPLETELY DEAD. It has no shape. They go through the motions.
As the director, it is your job and responsibility to find a way to wake people up, whether they are in the congregation or in your band.
In my choir director days, one of the choir’s favorite songs was Richard Smallwood’s “Total Praise.” (There’s a notorious tenor note that most of them get wrong. “Time… of *THE* storm.” Just an aside.) After we did the verse, I would always go and repeat the verse A Cappella, so I could take my hands off the piano and direct the choir. Because they weren’t sure if I was going to be soft or loud or on what WORD I might do it, they would have to dial in.
If your band/choir/team starts to go on autopilot, do something unexpected to break them out of it. Dial in to the music.