In Clara Schumann's "Liebst du um Schonheit," the music coincides with the repetitive, exaggerated poetry. Ruckert's poem contains four couplets, each helping to build to the climax of the last couplet, which seems to hold the main idea of this song: love for love's sake. It could definitely be the two and a half minute theme-song for Isis and Osiris. Schumann sets Ruckert's poem very well by emphasizing the most important word, liebe, consistently using a vi 42 chord with a lowered fifth, then resolving it to the dominant. She writes this every time the poet says "oh do not love me." Although the "liebe" is the same, the text immediately preceeding ("oh do not") is modified rhythmically. Schumann keeping the same basic "ab" idea of the strophes in this song, but making minor changes classifies it as a modified strophic song.
One characteristic of this song is the major III used in measure 10 on "Haar," unusual for a major key. But then Schumann quickly switches back to the expected minor iii. Perhaps this part is trying to musically explain the poet's hesitation to ask for the love she really wants. The next line that rhymes textually does not follow the same harmony. Measure 17&18 goes from I-V, a typical progression. This is how the modified strophic works, rhyming in one way (with the words), but differing in another way (harmonically). Ironically, the form of the song captures the nervous excitement of the poem and the character's desire for love, but only if it's for the right reason (conflicting feelings).
The climax to the song, starting in measure 27 is the same as the lines before (I, vi 42-5, V) but given stronger dynamic and tempo markings in the vocal line. The pianist doesn't need directions to get a stronger feeling because the texture thickens, any additional direction would make it difficult for the singer to be expressive or heard. The next measures, 31-33, Schumann uses motivic parallelism to support the repetitive, almost desperate text. Schumann's writing implies that the performers should be prepared to have a different interpretation for each measure. I wouldn't look at it as one long phrase, but rather as seperate declarations leading up to the "I'll love you evermore." My conclusion is provoked not only the motivic parallelism, but also the directions in the score. The accent marks in ms. 31 suggest that Schumann was more concerned with portraying text and a certain mood or idea in this section and was less concerned with the musical line.
Measures 34-36 are very different from the rest of the song, especially in the piano. The entire song the piano has had block chords with arpeggiation, lots of non-harmonic tones- in general pretty elaborate. Starting in measure 34, eighth notes plunk out the necessities of the chords: iihd65, I64, V7, I, giving the singer a chance to finish. The piano goes back into its original complicated texture in measures 36-38, but really "winds-down" a measure before the final cadence.
If I were to perform this song, I would not worry about the line so much and pay more attention to the dynamics and important words such as "nicht" and "liebe." I think that the "flowery" accompaniment is meant to be the nature portrayed in the poetry and how in the end, even nature(piano) succumbs to love(voice). Yes, I know it's very cheesy but it was the time. I wonder how a modern cynical audience would react to this interpretation. I only say this because I remember talking about "art for art's sake" in Dr.Balensuela's seminar last year- I think that can kind of be interpreted in this song! and I think our modern inclination is to say that such a romantic interpretation "waters-down" art. So perhaps your personal position on that particular topic could influence a performance of this song. For instance, if you wanted to take the cynical route, I could imagine a sarcastic interpretation. Especially with fantastical references and the personification of nature in the poem. One way to pull off this interpretation would be to emphasize the modification of when the vocal line starts, sometimes starting the phrase on the downbeat, sometimes on the off-beat. Writing that modification, Schumann paints the overall hesitation of the song- but it could also be perceived as indecisiveness, or anxiousness. If I were to perform the "hesitation" interpretation, I would start the phrases that come in on the off-beats "piano , or mezzo-piano." If I were to sing the sarcastic version, I would come in stronger, almost as a response to piano's block chord on the downbeat.