I don’ think it’s the instrument that people object to. It’s the sacredness of the music being played on those instruments.
No one would want to hear even the most beautiful organ playing sports arena music at Mass!
Cara Serrano has got it!
@ ethelzguy: Again, the instrument is an extension of the musician - the musician has the last word on whether the sound that comes out will be sacred. You’d make a great employer, you know what “equal opportunity” means

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I’ve been to Mass in a great stone Cathedral here enough times to have lost count. On one occasion during the celebration of the Holy Sacrifice of the Mass, a girl I was with had to leave - she said the organ music was so loud it was giving her a headache.
On another occasion the music was so loud I had to cover my own ears with my hands (and I’d played on stage with rock musicians before who weren’t as loud…go figure).
Approximately 8 or 9 years ago (when I was still a little bit active musically) I was asked to play some guitar music for a celebration of the Way of the Cross in an auditorium full of palliative care patients. That was a really delicate deal. I asked the priest who led the celebration beforehand exactly where he thought the music should be inserted, and then proceeded to suggest how it would best be done in a way that wouldn’t interfere with any of the other elements.
As the patients were entering the auditorium, I played several standard selections that are in the CBW (no lyrics just one guitar doing an instrumental version[if it makes a difference - I prefer to play by ear]). Among the entrance selections was an instrumental version of “Faith of Our Fathers.” One of the patients - Lena (102 years old at the time,and who had played the organ professionally in Church Cathedrals all her life) beckoned me over when the “Way of the Cross” had concluded. She said, “I really liked it when you played Faith of Our Fathers.” That was one of the nicest compliments I, and the guitar as a liturgical instrument have ever received.
Back to the ear-piercing organ music. Musically speaking, just as there are certain things which “get people going”, there are also things which can “turn them off”.
There are a lot of things which can “turn people off” musically. I’ll only mention two here:
The first is
volume. It’s a never fail no-brainer. Everybody has their limit. Turn it up loud enough, (even if it’s a cassette of Pope John Paul II singing the Pater Noster [really - I used to have one]) and it becomes unbearable. At an excessive volume any and every sort of music becomes an assault on the ears; an assault against which there really is no defence other than to cover one’s ears with one’s hands.
The second is a little more subtle…it’s
percussion. It can be linked to volume. When it is done badly, it can often be perceived as noise (not such a good liturgical additive). This is the disadvantage a guitar has regarding its proneness to “turning people off” in the liturgy. Many musicians strum a guitar. Strumming is percussive (and let’s face it if it’s done badly or in bad taste, sometimes it’s just plain
cussive.)
Suppose now I’m about to play a song during the liturgy of the Eucharist and I start up a Chugga ! Chugga ! Chugga ! rhythm on the guitar. How many people, right away don’t want to sing/pray to that rhythm? But I’m forcing them to listen to it. Then let’s say my meter is not so steady and a few more (@Cat) are saying interiorly “I’d like to sing but you can’t keep it steady.”
Add one slightly out of tune string and a consequential sung sour note and before you know it, I have the whole congregation praying intensely**…for the end of the song to come**!
Of the so many guitarists I’ve met , seen , heard, played with, roughly 80 % were quite accomplished lead gutarists (for playing melodic solos). However more than half of these barely could have been considered adequate rhythm guitarists. Now rhythm guitar is the type of guitar that is commonly played most of the time for liturgical music (except perhaps for rare virtuosos) and, as explained in the previous two paragraphs, it’s percussive…that’s why they call it
rhythm guitar. And like excessive volume, but not to the same extent or intensity, rhythm has the potential of being percussive and or invasive.
The general mindset today says" rhythm guitar[chords], or lead guitar [solos]"
There is another type of guitar. For liturgy, I’d call it background guitar (some types of fingerpicking could qualify as this). To me background guitar is the conscientious effor to remove the percussion from the playing as much as possible, providing the chords for the congregations musical orientation to facilitate participation (with perhaps the occasional slight melodic movements within the chord). When this is done, most of the “stiffness” of a strummed guitar is removed. The difference is that you’re left with something that can be wrapped around the song and help it flow; rather than trying to “drive” the song from start to finish.