The preoccupation about the organ and permissible musical instruments in general, in the context of their use in the Liturgy, obtained its vigour in the ongoing (at that time) disparity of the reaction towards the question. On one hand, there were churches that approved their use; on the other, there were churches that condemned the same. Annus, qui hunc wisely obviates identifying which position is correct. Rather, it isolates the graver issue and laments the ongoing failure to remedy it: both unaccompanied chanting and accompanied singing, as well as polyphonic music, were, in the practice of that time, impaired. The admission of the organ into church music had seemingly opened the floodgates of musical vanities that, in a short time, church music appeared to arrogate upon itself the obscene right to fraternise with theatrical music. The problem was so pivotal that Benedict XIV concluded that no one would object if a distinction were to be established between the music proper to churches and that which was proper to theatres. To winnow out the chaff from the grain, so to say.
The opinion, therefore, that they—who, from those climes where there is no usage of musical instruments, travel to Us and to Our cities, in whose churches they shall hear polyphonic music not different from those in theatres and other profane places—are to receive from Us, anyone can attain by himself with easy conjecture. Even foreigners will come, there is barely no doubt, from those regions in whose churches singing and musical instruments are used, as in like manner is usually done in some of Our places. But if these men be prudent and pious, they shall indeed sorrow over not finding, in the singing and in the sound of Our churches, that remedy that they hoped to be brought forth for curing the wrongdoing of their churches. And indeed, having neglected this controversy, in which some bicker amongst themselves, some of whom disapprove and criticise polyphonic music and the use of musical instruments in their churches; while some approve and praise them: there is certainly no one who would not desire some distinction between ecclesiastic chant and stageworthy crooning, and would not doom theatrical and profane songs to be not tolerated in churches.
Quam igitur opinionem de Nobis accepturi sint, qui ex illis regionibus, ubi nullus musicorum instrumentorum usus est, ad Nos, nostrasque Urbes proficiscuntur, in quorum Ecclesiis concentus musicos audient, non secus ac in theatris aliisque profanis locis, facili quisque per se coniectura assequi potest. Venient etiam, haud dubium est, exteri ex illis regionibus, in quarum Ecclesiis cantus et musica instrumenta adhibentur, perinde ac in aliquibus nostris fieri solet. Sed si isti homines prudentes et pii sint, dolebunt quidem in cantu et sono Nostrarum Ecclesiarum, remedium illud, quod malo suarum Ecclesiarum curando afferri optabant, non invenisse. Etenim, omissa controversia illa, qua nonnulli inter se decertant, quorum alii cantum musicum et musicorum instrumentorum usum in Ecclesiis reprobant ac vituperant ; alii vero probant ac laudant : nullus certe est, qui inter cantum Ecclesiasticum et scaenicas modulationes discrimen aliquod non desideret, et theatrales profanosque cantus in Ecclesiis tolerari non condemnet.
The list of what impair sacred music has been evolving, that it would seem counterproductive to even admit that there is an impairment. Many of us perhaps know of the anecdote of the Palestrina intervention which saved polyphony from being cast into the exterior darkness, upon which action greatly contemplated Pope Marcellus II, to resolve the question pitting the intelligibility of the text against the aesthetic value of the music. Then came the temptation to assimilate techniques and forms that are more attuned to the atmosphere of the theatre than to the hallowed precincts of the church, a problem that had been prefigured in the decretal of Pope John XXII. Now, with musical instruments almost universally accepted in the Church, the guitar, together with the drums, is another pathogen worthy of destruction. Let us heed the call of our holy popes and resist the tide that attempts to erase the distinction between church and tavern, to literally assert the omnipresence of God in order to erode the importance of the consecrated edifice, and having thusly demolished the Church, to finally declare that there is no enclosure anymore brandishing an exclusive claim to salvation. Steadfast in our faith, singing wisely, let us fight this good fight!
Ut in omnibus laudetur Dominus.
Reference: Benedict Pp. XIV, Encyclical Letter Annus qui hunc, 3, near the end.