The Council of Trent on music (1562):
All things should be so ordered that the Masses, whether they be celebrated with or without singing, may reach tranquilly into the ears and hearts of those who hear them, when everything is executed clearly and at the right speed. In the case of those Masses which are celebrated with singing and with organ, let nothing profane be intermingled, but only hymns and divine praises. The whole plan of singing in musical modes should be constituted not to give empty pleasure to the ear, but in such a way that the words be clearly understood by all, and thus the hearts of the listeners be drawn to desire of heavenly harmonies, in the contemplation of the joys of the blessed . . . . [Musicians] shall also banish from church all music that containes, whether in singing or in organ playing, things that are lascivious or impure.
The Palestrina legend as recounted by a Jesuit priest in 1629:
[Pope] Pius IV, a most serious-minded pontiff of the church . . . had noticed for some time that music and singing in sacred places was very little else than an abundance of delicate diminutions and vain adornments to the words, from which no benefit of piety came forth to the listeners. He then determined to set the question of banishing sacred music from the church before the Council of Trent, and he had already mentioned his aims in meetings with various cardinals and other prelates. When word of this came to the ears of Giovanni Palestrina . . . he quickly set himself to compose some Masses in such a way that not only should the combinations of voices and sounds be grasped and remembered by the listeners, but that all the words should be plainly and clearly understood. When the pontiff had heard these works and had seen how useful they could be for the divine service . . . he changed his mind and determined not to banish sacred music, but to maintain it. This was told by Palestrina himself to a certain member of our society [i.e. the Jesuits], from whom I heard it.
Palestrina's preface to his Second Book of Masses (1567):
To Philip of Austria, Catholic and Invincible King:
Since the utility and pleasure afforded by the art of music is a gift of heaven greater than all human teaching, and since it is particularly valued and approved by the ancient and authoritative writings of Holy Scripture . . . I have considered it my task, in accordance with the views of most serious and most religious-minded men, to bend all my knowledge, effort, and industry toward that which is the holiest and most divine of all things in the Christian religion--that is, to adorn the holy sacrifice of the Mass in a new manner. I have, therefore, worked out these Masses with the greatest possible care, to do honor to the worship of almighty God, to which this gift, as small as it may be, is offered and accommodated. And these products of my spirit . . . I decided to dedicate to your Majesty, who has taken your own name from the tradition of the Catholic faith, and who also guards the purity of the orthodox religion most ardently, and who honors and adorns the sacred services through the works and ministrations of most excellent musicians. Accept, then, most mighty and God-fearing king, these my labors as testimony of my perpetual loyalty toward your Majesty--and accept them with that kingly greatness of spirit with which you are wont to receive such gifts. If these labors should please you, then I would consider it their greatest success if they should satisfy your judgement. If they should not please you, then nontheless my loyal affection will not waver toward the magnaminous and noble king . . . . Farewell, ornament and bulwark of all who bear the name of Christians.
Palestrina's letter to the Duke of Mantua (1568):
Illustrious and Most Excellent Lord:
I am certain that my small knowledge will not be comparable to the great desire I have to be of service to your Excellency, yet it seemed to me rather better to show my insufficiency than to hide it and to be ill mannered. Since I have been ordered by so excellent a lord as yourself . . . to compose the Mass that is enclosed here, I have fashioned it as I have been instructed . . . . If in this first attempt I shall not have fulfilled the wishes of your Excellency, I beg you to inform me how you prefer it--whether short, or long, or written so that the words can be understood. I will do my best to serve you according to my ability, which I will always expend in the service of your Excellency. I kiss your most illustrious and excellent hand.
Source: Giovanni Pierluigi da Palestrina, Pope Marcellus Mass, ed. Lewis Lockwood (New York: W. W. Norton, 1975), pp. 19, 30, 22-24.