I guess the most interesting phrase is " provided they are truly apt for sacred use or can be rendered apt.". This suggests that some instuments would not be considered apt, or suitable, and cannot be rendered suitable. What might those be? Let’s say a bishop thought that electric guitar is not suitable. What could someone suggest doing to it to render it suitable? Why are some instruments NOT considered suitable? Because they don’t enhance the reverence of the Mass, or they are distracting?
I know that one of the biggest criticisms or praises of this from various church musicians I work with is that it is ambiguous. For example, what one person considers “truly apt” for sacred use, may not be considered such by another. It leaves the door open. For converts to the faith from a more evangelical or charismatic denominations, they have a religious music tradition which uses a lot of instrumentation, style of performance and composition that would be completely ok for use to them in a liturgical setting because they were used to hearing it at their Protestant services. For a cradle Catholic who has never heard that kind of music or instrumentation at mass, it would sound completely inappropriate and to some others borderline sacrilegious.
As a person who was brought up in the 80s and 90s with a lot of leftover folk-like hymns, some traditional hymns, the guitar, piano and organ, I personally never felt completely comfortable with a guitar at mass even though our parish did have some masses with them. When they started doing the teen masses at my church with complete bands, that totally threw me for a loop and sounded way too secular for me. Yes, I know strange for a teen and a young adult. For a number of years into my 20s it would even cause a physical reaction manifested through nausea and anxiety (anxiety mostly due to the loudness of the music ) and every time I’d attend a mass like that, I’d end up in the bathroom. I ended up just not attending a mass that had that kind of music until I was able to get the nausea and anxiety under control. Now, if I ever have to do it, I know how to block it all out.
I do think that many kinds of instruments, including the voice, can be rendered appropriate. I’ve been a proponent of that for a while. It goes way back when the Church asked composers to render polyphony appropriate for liturgy and it eventually was, after being banned by the Church by a few popes.
My particular instrument of expertise is the voice. I personally believe there are certain ways of using the voice to render it appropriate for liturgy and will do my best to make it happen. Full-blown operatic singing is not appropriate for mass, no matter how much I can and love singing that way. That style was purely developed for secular singing. There is a difference with the singing style of the Verdi “Requiem”, for instance, and the Faure “Requiem”. The former is all about passionate singing. You can’t sing it any other way. The latter is more “contained”, not filled with unbridled passion in the singing style. If you sing it like the Verdi, it would sound ridiculous.
Most of liturgical music does not call for operatic singing, anyway, and the style doesn’t sound as good in the vocal range of most hymns. You also shouldn’t sing like that when chanting and should try to employ more of a straight tone voice or a voice with less vibrato. Classical vocal training is important to understand the differences in style just as classical training of any instrument is important.
In their pure forms, pop, rock, Broadway style and other kinds of belting and chest voice singing also really isn’t appropriate because those were also meant for secular singing. Many people who have untrained. natural voices, especially when you get the person to stop trying to sing like the singers on popular music stations, from musicals or operas, actually have beautiful, pure sounds. It may be raw, but it can sound lovely in a choir or even as a cantor if a singer has a particularly natural beautiful voice.
With other instruments and compositional styles, I think almost any instrument can be used as long as they do things with the instrument to make it sound as little like the popular and other secular music going on at the time, whether that is opera, broadway, pop, country, etc. I personally feel that if it sounds like you can take it out, change the words and put in on a station without anyone think that it might sound like it came from a liturgy, then maybe we should rethink about using it OR try to render it “apt” for liturgical use, whether that is changing the way you use your voice, changing the composition itself or playing the instrument a different way to make it happen.
I say this as someone who prefers the organ (at least a well-played organ) at mass. I have heard other instruments played beautifully and appropriately at mass, including a classical guitar, which changed my mind about no guitars at mass. (Unfortunately, most guitars I’ve heard at mass doesn’t like the person I worked with. He was up there with all the best organists I’ve worked with.)
