You could consider PICARDY to be in the Dorian mode, couldn't you? In which case both melodies would have the same "final." Making them have the same "key signature" would make the chant too high to sing comfortably (or PICARDY too low).

Sam Schmitt

I mean you could "consider" PICARDY to be in the Dorian for purposes of combining it with the chant - after all, the sixth degree in Dorian can be flatted (flattened?). There is no aeolian mode in Gregorian chant, though there are some pieces in the first mode where the sixth degree is consistently flatted, making them sound "aeolian." Of course, the "Crux fidelis" is not one of those pieces - still, I think it work well with PICARDY (and is anyone listening really keeping tracks of the various modes?).

Sam Schmitt

In The Hymnal 1982 the Crux fidelis (Pange lingua gloriosi proelium certaminis) is set to the chant melody of Pange lingua gloriosi corporis mysterium.

I suspect that in most places the latter is sung in most places on Maundy Thursday. If they can sing the melody on Thursday night, they can sing it on Friday.

Perhaps there is some precedent for using this melody for both texts. I don't know. I suspect, however, that Winfred Douglas, who edited the Hymnal 1940, would not have paired this tune with "Crux fidelis" without such precedent.

Every great Feast has its songs, its musics, without which the celebration would not be complete. Some are Hymns such as Adeste fideles and Easter Hymn, some are chants such as Puer nobis, Hosanna filio David, or the Golden Sequence, or it might be an anthem such as Sicut Cervus, Exsultate justi, or Like as the Hart. We could each add numbers more of musical exemplars the absence of which leaves 'something missing' in a given celebration. But, certainly Crux fidelis is such a hymn the absence of which would leave the Good Friday Liturgy literarily, musically, aesthetically impoverished - in-complete, not completely done. And to Crux one might add the Gregorian Reproaches in their Greek and Latin (or Greek-Latin-English!) It says something sad about the state of our religious culture that most people do not seem to know much about, or identify with, more than a basic repertory of Christmass & Easter music. I dare say that they dont look forward to singing the sequence on Pentecost, nor Crux and the Reproaches on Good Friday with the same anticipation which they reserve for Adeste fideles or (cough) Grosser Gott. This is truly sad because they SHOULD! So many have been remiss in communicating our Patrimony to the next generation and if this isn't remedied the culture will eventually die, or, simply, atrophy. They have been fed out-sourced pablum for forty years ("forty years have they grieved thee'!) and there is no time to lose. They must be given real food, and a vision, lest they perish. Yes, Crux fidelis should become a thing people look forward to the way Lutherans look forward to O Sacred Head Surrounded - and for the same reason: someone put it in their blood and things aren't complete without it. (This was going to be just a few words of encouragement to Felipe in his imaginative alternatim treatment in preservation of ONE of the things every Catholic ought think about when Good Friday is mentioned.) Godspeed!

This?

Speaking of Crux Fidelis and Picardy,
for a beautiful experience try singing Mortal Flesh to Crux sometime!