Go on YouTube and search for a piece of polyphony or a specific Gregorian chant.I say: Heck yeah!
In most cases, you'll find recordings (even if they're not perfect).
This is a wonderful thing and makes our lives quite nice and easy.
Looking at a score for the first time in your parish office with the noises of an office all around you (chattering co-workers, photocopier, bookkeeper playing praise and worship music, etc)? Throw on some headphones and listen to a recording. Much easier than trying to hear the schola in your head sing the score with the background noise.
However, occasionally you will run across a piece of sacred music (Song X) that has no recording on YouTube, no sample MP3, etc.
How can you help make sure this doesn't happen to the next person who comes along?
Record your (hopefully competent) choir singing the (hopefully public domain) piece! Upload it with a clear and easy-to-search-for title.
Then bingo - six months down the road some Music Director from the other side of the country who searches for Song X will find your video! You'll have helped a colleague and you don't even know it.
Orlande de Lassus has a number of polyphonic Offertory propers. Almost none of them have recordings available online. I will begin the process of putting them online this weekend with his Perfice Gressus Meos.
The next time you find a piece of music that doesn't have a recording online, do the same.