I've set this poem to music twice, each time completely differently. I wrote a version (with water sounds and tin whistles) as part of music for a dance piece (which included a setting of Rilke) by Project in Motion in New Mexico. This setting was lyric and very water based. (The show was called "Aqua.") It's here:
The second setting is spooky and shamanistic, but created with voice synthesis and drum sounds.
I like both versions and find it really interesting how a single poem can have such a different effect.