Book excerpt: 'The Art of Songwriting' is a comprehensive guide to life, art and making great songs.It's not about chasing a hit song. It's not about theories that are interesting but no use filling the blank page. And most of all -- it's not just about the craft of songwriting.It's about how to create, think and live like a songwriter. It's about being resilient, innovative and passionate about what you make. It's about how artists can change the world -- and why they should.