In the latest issue of Acoustic Guitar magazine, there’s an interview with Richard Thompson. In his answer to a question about how much his songwriting is driven by knowledge and how much by experimentation, Thompson says something that photographic artists can take to heart. Just replace the musical references with photographic ones.
There are many ways to generate ideas in songwriting. You could visualize it as different doors that arrive in the same hallway. It doesn’t matter which doorway you go through as long as you get into the room. A chord structure is a way to start a song, and so is a lyric, a melody, a bass line, or a repetitive riff. It doesn’t really matter which one you start with as long as you start. If you don’t start, well, that’s just too bad. You’re going nowhere.
The entire interview is available at http://www.acguitar.com/article/default.aspx?articleid=27502 It’s worth reading, even if you know nothing about music.