A regular Pray Tell reader writes:
We are considering vesting our choirs of boys, girls, men and women, and I’ve been waffling between cassock and surplice, alb alone, and alb with a colored scapular over the top. I am attracted to the scapular not only because it adds a “splash of color,” but also because it represents (especially to those wearing it) a yoke of discipleship and an apron of service. Still, I’m nervous about co-opting a non-liturgical element of religious habits for a liturgical purpose.
For your reference, Sing to the Lord: Music in Divine Worship, the 2007 document of the U.S. bishops, says this at no. 33:
Choir and ensemble members may dress in albs or choir robes, but always in clean, presentable, and modest clothing. Cassock and surplice, being clerical attire, are not recommended as choir vesture.