Brentano joined the Schlegel circle in Jena in 1798. In 1801 he met Achim von Arnim (who was to marry Brentano’s sister Bettina in 1811) and with him produced a celebrated collection of modernized versions of German folksongs and poems called Des Knaben Wunderhorn (The Boy’s Magic Horn) in 1805–1808. In 1804 he married Sophie Mereau (see p. x); she died two years later. Though he wrote novels, novellas, and plays, Brentano is most admired now for his lyric poetry, much of which, in fact, was contained in his prose works. As it originally appeared (untitled), this poem was a musical duet in alternating couplets. Johannes Brahms set it for six voices in 1859 (op. 42:1).