Two ways if I understand you right. One, encourage them to listen to the songs that are chosen repeatedly; Karmel says at least 20 times. two, have them do a song analysis of the song and how it made them feel (what they got out of it). then hold them responsible for helping to coreograph some of the music and making sure that their moves match the since of the song...well mabe thats three or four things...where are they spiritually that probably should have been first. Set some time aside during your practice to hear from and meditate on God during that time have them listen to different music and worship God to it. This is not a time for you to critique rather a time for God to move and for them to realize that they can do something different. Hope this is what you were talking about.
Sonji