I’ve added a podcast to the resource page which you might find interesting. Square Notes: the Sacred Music Podcast was launched very recently, and plans to discuss topics such as Church documents on sacred music, the music of certain composers or eras, Gregorian chant, the role of music in Catholic education, and techniques for directing a better choir rehearsal (from their about page). There will be interviews with bishops, priests, music directors, teachers, composers, philosophers and theologians, along with others who have been strongly effected by sacred music. Subscribe to catch each new episode as it is made available.
Visit their website for more details. Happy listening!