When music goes wrong.
In particular, we eager singers learned to limit our utterance of sibilant sounds. "Only every other one of you should pronounce the S," ordered the choir director. He was hoping to eliminate the prolonged hissing that emanates from the choral body when some of its members can't manage the rhythm.
Another problem was popping P's. "You sound like somebody's walking on bubble wrap!," another teacher groused.
"You are singers, not librarians!" commented one beleaguered hopeful purveyor of a quality performance. "Enough of the shushing!"
If the remedy is delivered properly, the audience never realizes the extent to which the choir members eliminate sounds as they sing. In Randall Thompson's inspiring choral rendition of Robert Frost's poem, Choose Something Like a Star, nobody notices that only half the choir is actually singing the "s" and "p" sounds:
"Oh tar, (the ferret one in ight),
we grant your loftineh the right
to some obkurity of cloud . . .
It will not do to eak of night,
in dark i what bring out your light.
Ome mytery become the roud . . ."