The Secret Life of Lyricists

What makes a great song lyric? Is it the same process as writing a poem? Does it need to rhyme? Does it need to mean anything at all? Julie Hill asks musicians and music lovers about some of their favourite wordsmiths in song, and along the way discovers the mysterious concept of glossolalia; some great misheard lyrics, and meets the man partly responsible for John Mayer's Grammy winner 'Your Body Is A Wonderland'.