Post by REPGerman has a reputation for being an ugly-sounding language, something I've never understood. To me, it sounds pure and mellifluous. Given a choice between hearing poetry read in German, French, or Italian, I would choose German almost every time.
REP
Not sure I'd choose French, and I grew up the nearest thing to a native speaker. It's smooth-sounding, certainly, but very formal (probably derived from the dominance of classical models) and with a very limited vocabulary, which restricts its variety of sound. Occasionally somebody like Baudelaire or Rimbaud gives it a kick in the pants, but not often enough. Italian is more histrionic, and certainly has a better vocabulary, but again the classical influence makes the line that bit too mellifluous, as if about to burst into pure song; I note that there was a huge fashion in the 19th century for improvised poetry half sung to harp accompaniment (one such fashionable poetess is depicted in Rossini's Viaggio a Reims), and I think this lingers. But my Italian's not fluent, so maybe I miss the subtleties. Welsh is perhaps the most amazingly liquid language there is, but again its poetry seems more than haldway to song.
German, like English, seems to have a lot more variation; it can sound harsher, especially deliberately so in 20th-century verse, but romantic stuff, Uhland and Heine and the like, does indeed sound fluid and mellow to me. But a lot depends on the poet; Russian *is* a harsh language, much more so than normal German, yet Pushkin or Pasternak can make some incredibly beautiful sounds. And even Danish, which its speakers often call a throat disease, can sound surprisingly musical in good verse -- although one of my friends reading in a broad Jutland accent full of glottal stops isn't for the faint-hearted! All the same, and allowing for bias, I feel that English creates the most convincing balance between the mellifluous and the expressive -- English English, that is, from about Shakespeare onwards. Chaucer sounds closer to German, with the old Anglo-Saxon still poking above the surface here and there.
Medieval Scots English, like Dunbar, and more modern, like Burns and MacDiarmid, relies on its roughnesses to some extent for its rhythms and emphases. I find the same, to a lesser extent, in German -- one reason Goethe's deliberately gruff Knittelvers and Wagner's Ring libretto sound that shade less emphatic in English, even when the words and syllable count are quite similar. So:
"Ich bin der Geist, der stets verneint..." as opposed to "I am the spirit, that all denies..."
"Zu spat kam ich..." as opposed to "Too late came I..."
That may create some of the harsh impression.
Cheers,
Mike