If you enjoy eavesdropping, here’s a rehearsal excerpt (mp3) of my volunteers singing the exercise I posted last week. This is the second time we’ve used it, and I can definitely hear improvement. You can download this choral warm-up for free.
Pope Saint Paul VI (3 April 1969): “Although the text of the Roman Gradual—at least that which concerns the singing—has not been changed, the Entrance antiphons and Communions antiphons have been revised for Masses without singing.”