i write music and lyrics independently, so sometimes the lyrics happen first. but even when i'm not writing to a melody or chords or a riff, i know that the lyrics will be lyrics, so i write to a structure that's sort of dictated by the first couple of lines. when it's time to put them to music, the structure might well change based on how singable they are (or aren't), and sometimes that does paint me into a corner where i can't find the way to add or subtract syllables to make a line work with the music. but generally i can make the lines scan, with a bit of effort.
this is one i'm working on now that started from lyrics, then got shaped by the music afterwards: http://tempusfugitives.articulateima...eVeryRuff1.mp3
based on a mood i experienced in a hospital waiting room at 4am, filtered by way of wim wenders' 'wings of desire'. i haven't decided whether i'm going to polish it or not, but i wanted to hear it so i recorded the demo to see how it would work.