Those who know me know that I do not use the interrobang lightly.
If you’re still using your crusty old 1974 Solesmes Graduale Romanum (or worse — a Liber Usualis!), you might be under the impression that the Offertory chant consists only of an antiphon without verses. Au contraire! Since as far back as 1935, we have had a collection of offertory verses in modern notation which is now widely available thanks to the folks at CMAA. This collection served as the basis for the rare Offertoriale Triplex, which was later improved upon (in my opinion) in the editions available online at Gregor und Taube.
Take a listen to the Offertory Confirma hoc sung by three cantors at Notre Dame des Victiores in San Francisco. I’m not sure who the soloist is, but he sure does sound handsome! (And I’m sure if he had to do this over again, he would have used a little less separation on those groups of strophae before posting a recording on his Gregorian semiology blog for the entire world to hear. Too bad we may never know who it was).