Pope Benedict said it. Really.
(E)cclesial authorities must undertake to guide … the development of such an important form of music, not by ‘freezing’ its heritage but by seeking to combine the legacy of the past with the worthwhile novelties of the present, so as to achieve a synthesis worthy of the exalted mission [sacred music] has in the service of God.
The context is the Holy Father’s recent visit to the Pontifical Institute of Sacred Music.
Catholic Sensibility 
Todd, dear Todd,
Yes, I agree that His Holiness, Benedict XVI, said that we should not only have a liturgical music which is rooted in the past, but that it should have a continuity with the present.
But that is what was said by everyone from His Holiness, Pius X, through John XXIII, Paul VI, John Paul I, John Paul Magnus, to the present, and the liturgical directives of the Second Vatican Council and afterwards.
We’re waiting for you liturgists finally to present the whole picture: the chants of the past, the polyphony of the mediaeval, renaissance, and enlightenment ages, the hymns of the 18th, 19th and 20th centuries, and the best of what has been written in these times. I personally think that “Gift of Finest Wheat” and “And Holy is His Name” can stand against any of the best.
We’re waiting.