"I've been very happy lately, and that's worrying," KT Tunstall told me. "It's much easier to write sad songs than happy songs. Happiness makes you want to be present, but pain makes you want to escape. And music has always been a way for me to get out."

Tunstall is adamant about not writing every day. "I love doing nothing, so mindless puttering is especially effective. When she finally sits down, she has rules: no blue pens, and the paper has to be unlined. Why unlined? Because she hates being told what to do, and lined paper represents a means of control. 

Tunstall is celebrating the 20th anniversary of her debut album Eye to the Telescope with a deluxe edition out now.