Music Composers Unite!
The main tip I have for you is being very careful with your text setting. Make sure all the strong syllables are on strong beats and weak syllables are on weak beats. Its always a good idea to even highlight all the strong syllables before starting.
When choosing text, just go with what you like. All poems and text have their own list of challenges when it come to setting them to music. There is really no science behind it.
When it come to copyright, just contact the person or publisher that own the copyright and ask for permission, they will send you some paper work to sign and your done. Some are easier then other to get permission from.
Jon Corelis said:
Many modern serious composers seem not to pay enough attention to the sounds of the lyrics -- not just accent, but things like alliteration, assonance, hiatus, and the use of liquids or sibilants.....My advice to someone setting a poem to music would be to repeatedly read the poem aloud.... Too many composers seem to write music for the poem they have read, not for the one they have heard.
And I would also suggest checking out YouTube to see if there are any recordings of the poem(s), and listen to a couple of different interpretations. It can be a bit hit and miss, but you can often come across an actor/actress whose reading of the poem brings it alive.