Greetings,
I found this helpful forum and just joined a few weeks ago. Appreciate any assistance. I’m trying to find any sheet music (any notation) of the Old Roman Kyrie used in the Mass of the Nativity, as featured on YouTube posted by “Callixtus”. Tried contacting them but no luck. Welcome any ideas on where in the public or private domain the notation for this kyrie can be found. Thank you so much

Steve Z

Yes that’s it!

Wow this is great! Thank you so much madorganist! I don’t see the melismatic “amen”s notes anywhere but that’s ok. You’ve given me a starting point that previously had me in the proverbial dark for over two years trying to find the notation. Thank you so much. I’ll peruse the rest of the document. Aren’t those Amen melismas hauntingly beautiful? Thank you so much for the Kyrie!

Ensemble Organum sing mostly from manuscript facsimiles, so those are the best source! You can buy their edited recreation of the Old Roman chant in Bodmer 74:

https://organumcirma.com/en_GB/produit/cantilena-romana/