In what century was the the style of voices popular that the Liebeslieder Walzer, Op. 52 was in?
Ländler The Ländler (] ) is a folk dance in  time which was popular in Austria, south Germany, German Switzerland, and Slovenia at the end of the 18th century.
Tonkunst Tonkunst, literally "The Art of Tone", is an obsolete term in the German language applied for art music of the 19th century, and often used in music history and musical aesthetic representations. It probably originated from the need to give the music a place among the classical arts like architecture, sculpture, painting, prose and poetry, and also recognize the composer or musician as a creative individual. The term is found for example in the inscriptions of the Walhalla memorial built in 1842, where a good example is Joseph Haydn, titled as "Doctor der Tonkunst" ("Doctor of Tone-Art"), and Ludwig van Beethoven as "Tondichter" ("Tone-poet"). Today the term is rarely used, but lives on, for example, in the name of the Tonkünstler Orchestra.