Catechism of the Catholic Church §2503 — excerpt
For this reason bishops, personally or through delegates, should see to the promotion of sacred art, old and new, in all its forms and, with the same religious care, remove from the liturgy and from places of worship everything which is not in conformity with…
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.
Also cites: SC 122-127