Back in March, I transcribed "When in the Hour of Deepest Need" and noticed a small feature about the first line. It's sung to this musical phrase from the tune "Wenn wir in höchsten Nöten sein":
The title line "When in the hour of deepest need" is sung to this phrase, with "deepest" sung to a group of descending notes (Bb A G), musically giving a sense of that depth.