65. In sung or said Masses, the organ, or other instrument legitimately admitted, can be used to accompany the singing of the choir and the people; it can also be played solo at the beginning before the priest reaches the altar, at the Offertory, at the Communion, and at the end of Mass.

60. The following principles for the use of musical instruments in the sacred liturgy are to be recalled:

a) Because of the nature, sanctity, and dignity of the sacred liturgy, the playing of any musical instrument should be as perfect as possible. It would be preferable to omit the use of instruments entirely (whether it be the organ only, or any other instrument), than to play them in a manner unbecoming their purpose. As a general rule it is better to do something well, however modest, than to attempt something more elaborate without the proper means.

b) The difference between sacred, and secular music must be taken into consideration. Some musical instruments, such as the classic organ, are naturally appropriate for sacred music; others, such as string instruments which are played with a bow, are easily adapted to liturgical use. But there are some instruments which, by common estimation, are so associated with secular music that they are not at all adaptable for sacred use.

c) Finally, only instruments which are personally played by a performer are to be used in the sacred liturgy, not those which are played mechanically or automatically.

B. The classic organ and similar instruments.

61. The principal musical instrument for solemn liturgical ceremonies of the Latin Church has been and remains the classic pipe organ.

C. Sacred instrumental music.

68. Other instruments besides the organ, especially the smaller bowed instruments, may be used during the liturgical functions, particularly on days of greater solemnity. These may be used together with the organ or without it, for instrumental numbers of for accompanying the singing. However, the following rules derived from the principles stated above (no.60) are to strictly observed:

a) the instruments are truly suitable for sacred use;

b) they are to be played with such seriousness, and religious devotion that every suggestion of raucous secular music is avoided, and the devotion of the faithful is fostered;

c) the director, organist, and other instrumentalists should be well trained in instrumental techniques, and the laws of sacred music.

- See more at: http://www.adoremus.org/1958Intro-sac-mus.html#sthash.iiLCSFtC.dpuf

c) The proper time for the chanting of the Communion antiphon is while the priest is receiving the holy Eucharist. But if the faithful are also to go to Communion the antiphon should be sung while they receive. If this antiphon, too, is taken from a psalm, additional verses of this psalm may be sung. In this case, too, the antiphon is repeated after each, or every second verse of the psalm; when distribution of Communion is finished, the psalm is closed with the Gloria Patri, and the antiphon is once again repeated. If the antiphon is not taken from a psalm, any psalm may be used which is suited to the feast, and to this part of the mass.

After the Communion antiphon is sung, and the distribution of Communion to the faithful still continues, it is also permitted to sing another Latin song in keeping with this part of the Mass.

(which are a useful addition to my Yamaha keyboard which only has two real settings on it: soft and loud.)

but it is not difficult to
perceive that there would have to be a great deal of sacralization before that kind of
music can legitimately cross the church threshold.