That though sounds like a fire in the grate. The fire in Scheffel’s refrain (if I read his poem correctly--- https://de.wikisource.org/wiki/D%C3%B6rpertan... ) alludes humorously, perhaps deflatingly, to the genius and inspiration of Novalis's Heinrich von Ofterdingen (“ein sagenhafter, historisch nicht belegter Sänger des 13. Jahrhunderts”—Wikipedia). (What made Scheffel in 1904 recur to Novalis's figure I don't know.)**
I wouldn’t have thought it’s worth trying to match the rhythm of the G. hendecasyllabic lines (as Ferenczi transcribes them; in Scheffel’s poem actually four not two lines).
The pentameters in #1 aren’t regularly iambic but:
spondee ǀ iamb ǀ trochee ǀ trochee ǀ iamb
– – ǀ ´– ǀ – ´ ǀ – ´ ǀ ´–
Light crackling fire plays round strings and the hand
The initial spondee and the trochees with their stress on the first syllable of the foot give the line something of the energy of the dance.
#3 is back in [to?] the land
** Addendum---J. V. von Scheffel (1826--1886) evidently wrote the verses earlier than that (1904); it presumably appears somewhere in his Frau Aventiure: Lieder aus Heinrich von Ofterdingens Zeit (Stuttgart 1863).