From the standpoint of thematic reading, an Urlinie running down from ^5 misses too much of what is essential about the dramatic progress of the song in terms of motive and the play of register. "Misses" is not quite right -- what I mean is that an analysis grounded on such an Urlinie necessarily misconstrues the song and its elements.
The introduction announces three registers with distinct materials: I've labeled them Bass, Tremolos, and Bell. The voice (system 3) occupies the space between Tremolos and Bell (assuming the singer is meant to be female, a reasonable assumption given the identity of the poem's narrator). The Surprise moment comes in the second system, when to Bell is suddenly appended a motive that is a loose inversion of Bass, drawing attention to the relation of Db and C, which I regard as the crucial design element in the upper most voice, whether that line is in the keyboard or the singer's part. (L in the third system is a Leittonwechsel transformation, made directly as it could be in Tremolos.)
The static register of the voice -- as I wrote in the earlier post, if I were reading this with proto-backgrounds, ^1-^5 would be the overwhelming choice -- is pushed against by the same C-Db pair (above), and even more when Db = C# moves again, to D-natural (below). The harmony "breaks," however against "finster," where an R transformation in Tremolos is subverted by the G# in the bass. From that point the harmony moves toward a cadence; D-natural moves down again, finally reaching C; and the pinkie finger in Tremolos retraces its movements down from F# to F-natural.
When all this done, Surprise reappears, now in the voice, immediately after the keyboard's P-transformation (third system below). "Immerhin" here means "always" (or perhaps "constantly"), as the young nun introduces the comparison between the turbulence of the storm and her equally unsettled emotions. This moment of Surprise is remarkable, stands out as an island of calm, and promptly disappears as verse 2 gets underway in earnest.
A motivic detail of interest is Bell, which sounds as D5 but then is gone for several bars until it reappears at the moment of Surprise (below).
The second verse ends like the first, and the third verse, then, expands greatly on the P-transformation and the Surprise moment -- see below. The voice keeps pushing upward: C5-then D5-then E5-and-finally-F5 (circled notes), but as it turns out only the initial C5 is stable. E5 is reached at "Friede" but the harmony is C: I 6/4 that remains unresolved -- instead, an RP transformation takes it directly to A major (as V of D minor), then to Bb: V7 with the F5. This latter move is a PR transformation *if* you read only the underlying triads.
In all this, there is no suggestion of C5 (or any ^5) taking a significant role, though C4 in the middle of Tremolos does move to C# (enharmonically the Db of the beginning), which in turns drops back to C -- a nicely managed motivic statement.
The latter half of verse 3 was discussed in some detail in the previous post. Here I will note that Bell gives us a gesture C5-D5-F5 (connected boxes below), as pinkie Tremolos run from A4 up to D5 (connected circled notes). In Bell, E5 is skipped, not reached; and in Tremolos a reach toward E5 in the voice after the D5 is roundly subverted by Bass, which (finally) drops to Bb to define a functional triad plainly and then fosters the predictable patterns of voice leading to which Schachter draws attention.
