I'm entranced with the highly rhymthic chant melody for Nobilem Christi (hymn at lauds feast of a female saint). I know (from an informative article in Sacred Music Spring 2009) that that particular text dates from the 19th century. It's the melody that I'm after with an earlier set of words.

Any pointers will be gratefully received. And if you don't know the tune, look it up in the Liber hymnarius (p. 320) or your antiphonale and enjoy a nice sing.