Our poet has shown preference for the older German strophes which belong to popular poetry and had most firmly held their own in the spiritual song because of its relation to the Volkslied and also for the Nibelungen strophe of eight lines. Eighteen7373Goed. 10; 21; 23; 51; 125; 134; 58; 171; 190; 209; 253; 271; 298; 315; 317; 325; 331; 335. times he uses the well known seven-line ballad strophe and twice7474Goed. 60 and 71. the six-lined strophe of the Wanderlied "Innsbruck, ich musz dich lassen,"7575Regarding this melody cf. p. 100. which even as early as the Reformation had come into wide use in hymnody. He has also frequently employed the rhymed couplet in the four-lined stanza. The verse-structure in the remainder of his poems may generally be traced back to lays long-since 21 native to the church, though one strophe "Sollt ich meinem Gott nicht singen"7676Goed. 235. appears for the first time, as far as we know, in Johann Rist's7777Rist, 1607-1667. hymns. Realizing, furthermore, that a composition becomes truly a poem only through its harmony Gerhardt clung to the well known melodies, adapting his new text to them that through the music his hymns might the more easily become familiar. Thus he composed "Ein Lämmlein geht und trägt die Schuld" to the melody "An Wasserflüssen Babylon," and "O Welt, sieh hier dein Leben" and "Nun ruhen alle Wälder" to "Innsbruck, ich musz dich lassen,"7878Cf. p. 100. and in fact his hymns were known at first only through their musical setting. Like Luther, he wished to teach the people song7979Cf. p. 10. and it is evident that in composing he usually had some definite melody in mind, and what Johann Walther had been to Luther, Crüger8080Cf. p. 2. was to Gerhardt. To this choir master we owe the first significant publication of our poet's hymns. Many musicians have adapted his hymns to music; Bach made use of them in a number of his cantatas and his Passion Music;8181Cf. p. 43. and five8282From Goed. 25; 310; 150; 155; 158. times in his rapturous Weihnachtsoratorium do we find Gerhardt's words. Of recent musicians who have been interested in his poetry as a basis for their compositions mention must be made of Albert Becher (d. 1899), H. von Herzogenberg (d. 1900) and especially the Bavarian clergyman, Friedrich Mergner8383Cf. P. Gerhardt's Geistl. Lieder in neuen Weisen von Fr. Mergner. 30 ausgewählte Lieder von Karl Schmidt, Leipzig, C. Deichert, 1907. (1818-1891), who has so thoroughly caught the spirit of Gerhardt. As early as 1732-1800 six Catholic hymn books in quite general use throughout Germany had included in all, thirteen of Gerhardt's hymns, and "O Haupt voll Blut und Wunden" can be heard in many Catholic churches to-day, even in the Cologne Cathedral.8484Cf. J. Smend: P. Gerhardt u. das evangel. Kirchenlied in Der Protestantismus am Ende des 19. Jahrh. I, pp. 301, ff.