My / idle / fingers/_ould/spin/and/weave/
a /pattern/of/colours,/of/morn/and/eve,/
of/_u_/and/_o_n/and/changing/light/
amid/the/beech-leaves/_a_ing/bright.
Hmmm. I don't recognize this... it sounds very pretty, though, even in a half-constructed state!
Lay of Leithian, maybe?