The priests have certainly heard of it - - but I’m not sure all Church musicians have. And I bet that most parishioners have no idea that this exists. I bet there are many on this very thread (many of whom have strong opinions about church music) who don’t know that there is such a thing.
Caveat: I use the Graduale Triplex every Sunday at a Benedictine monastery and sing in a schola that also uses it, and I love Gregorian chant to the point that I also use for the Liturgy of the Hours every day.
However, I wouldn’t expect the average person in the pew to know about it. The Graduale Romanum (and even more so the Triplex variant) are not really intended so that the average person in the pew can use it. The Graduale Simplex was published for churches that didn’t have the resources for a well-formed Gregorian chant choir. It has much simpler chant settings based on the simpler antiphon formulae used for the Divine Office. But even that requires training.
And even if they did know about it, let’s face it the odds that the average person in the pew will sing along with the congregation in a complex introit, gradual or offertory are so small as to be infinitesimal. Even in monasteries, the Graduale would be the province of the choir monks only and not the lay brothers until post-Vatican II when that category of monk was gradually phased out and all monks became professed and participated in choir. Even then, not all of them will sing along with the schola. At the local abbey several monks don’t sing, but thankfully enough do that we have a very beautiful Mass in Gregorian chant.
The simpler settings of the Ordinary in Latin/Greek would certainly be within reach of most, but the Propers from the Graduale Romanum require a well-trained choir to execute properly. Bad Gregorian chant won’t sound any better than well-sung modern hymns.
At the parish level, to put it simply, if folks want to hear Gregorian chant, there is only one option: put together a schola and rehearse, rehearse, rehearse… and get some proper training.
It does nothing to complain about it. Do something about it. That’s what I did, I stumbled upon a schola that was doing it on a monthly basis at different parishes in their area. It was close enough to me that I could participate, so I joined, got some private lessons from the monk who was our choirmaster and also choirmaster of the abbey, and worked, worked, worked until it “clicked” and I finally got it right. Now I teach our schola and others how to psalmody.
Gregorian chant isn’t suddenly going to fall from the sky, and certainly don’t expect the pastor to suddenly pull a choir out of thin air.
If one can form a stable group to obtain an EF Mass, then surely one can assemble a schola of enthusiasts for the OF, and find a place willing to accommodate it at least occasionally.
All I ever hear on CAF is griping about bad Church music and preferring Gregorian chant, yet I encounter few people actually
doing something about it. What we did discover with our schola, is that there is a certain amount of nostalgia for chant out there and thus parishes willing to host us once or twice a year. Enough in fact, that we are able to put together an annual program of about 10-12 Masses, solemn Vespers and Lauds 3x per year, and a couple of concerts on top of that, including one sold-out concert where we were the only performers last winter.
But I doubt that there’ll be enough interest to sustain it in a parish every week. Those with that interest tend to gravitate to the EF. I do wish it would be used more int he OF but alas I have to be realistic.