So is it song or lyrics first when you write? Why is it that way? Or do you sing it as you write the lyrics?

I usually start with a musical idea like a chord progression and melody line. When I find the rhythm I like on da da das, I start the lyric writing. I usually have an idea of what I want the song to be about. I write out everything I want to say in a prose style first, then I write it out lyric style. It is really a simultaneous process but I always at least start with a basic musical idea.

Melody for me. from that, I have to pick out the chords that go with it and go from there. I'm not really schooled in theory, but I can "spell out" chords in my head so if I have no idea what chord I'm hearing, I can figure it out.

I guess I'm an oddball here, but I always start with lyrics and then set them to music. I guess once I know what the song/poem/lyrics are about, then I feel like I can tailor the music to fit that feel or idea. That could also be the classical training coming in. Rarely will a composer ever write text to an orchestral piece he's already composed. You "set a text" to a score that you already have in hand. I figure the process has become ingrained by this point.

For me, it depends on my mood and what I have available when inspiration strikes.
If I feel like it's a good guitar day, I can usually sit down and start hashing out riffs and putting together chords that make sense and then build my lyrical ideas off of that.
But other times, I'll start of just wanting to write. I'll take notes about what I want to write about, jot them down and go from there to build the song structure that I want. After that, I'm back at square one with trying to write guitar parts.

It's curious, and I've noticed in some of the workshops I've held at WVU, that very few people seem to write both at the same time. I've only ever encountered one or two who say that they actually write a few bars and then write the lyrics to those bars and move on slowly that way.

Is there anyone here who ever writes like that, or is that as rare as it seems? Has anyone ever tried writing like that?

I write like that sometimes. I will write a verse, then write the chorus, then write the bridge. I find that when I write like that the song makes more sense to me. Instead of having an entire musical idea from start to finish then setting lyrics or visa versa, I can choose where I want to go on the fly if you will. This is hard to explain...