According to a Second Vatican Council document: “In the Latin Church the pipe organ is to be held in high esteem, for it is the traditional musical instrument which adds a wonderful splendor to the Church's ceremonies and powerfully lifts up man's mind to God and to higher things.

“But other instruments also may be admitted for use in divine worship, with the knowledge and consent of the competent territorial authority, as laid down in Art. 22, 52, 37, and 40. This may be done, however, only on condition that the instruments are suitable, or can be made suitable, for sacred use, accord with the dignity of the temple, and truly contribute to the edification of the faithful.” (source: Constitution on the Sacred Liturgy – Sacrosanctum Concilium, solemny promulgated by His Holiness Pope Paul VI, Dec. 4, 1963)

According to GIRM (General Instructions for the Roman Missal): "While the organ is to be accorded pride of place, other wind, stringed, or percussion instruments may be used in liturgical services in the dioceses of the United States of America, according to longstanding local usage, provided they are truly apt for sacred use or can be rendered apt."