Musicae Sacrae §22

²² On this score sacred music obeys laws and rules which are no different from those prescribed for all religious art and, indeed, for art in general. Now we are aware of the fact that during recent years some artists, gravely offending against Christian piety, have dared to bring into churches works devoid of any religious inspiration and completely at variance with the right rules of art. They try to justify this deplorable conduct by plausible-looking arguments which they claim are based on the nature and character of art itself. They go on to say that artistic inspiration is free and that it is wrong to impose upon it laws and standards extraneous to art, whether they are religious or moral, since such rules seriously hurt the dignity of art and place bonds and shackles on the activity of an inspired artist.