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.
Helmut Kretschmar Helmut Kretschmar (born 3 February 1928) is a German classical tenor who spent most of his career performing in concerts and recitals with major orchestras and at important music festivals internationally. Although he focused his career mainly within the concert repertoire, Kretschmar did appear two times on the opera stage, notably singing in the world premiere of Arnold Schoenberg's "Moses und Aron" in 1954. Possessing a rich and warm lyric tenor voice, Kretschmar excelled in the concert repertoire of Johann Sebastian Bach, George Frideric Handel, Joseph Haydn, and Felix Mendelssohn. Also an admired interpreter of Lieder, Kretschmar performed and recorded a number of works by Franz Schubert, Robert Schumann, and Hugo Wolf.