Something I look for in music is complexity. Nothing too fancy -- but twists and turns that keep me on my toes are always a winner.
Westerman pulled off just the right balance between ease-of-listening and engaged-listening. His song "Confirmation" piqued my interest on first listen, and from there it grew and grew and grew. At this point I'm more familiar with the melody and I must say that every time it comes on I find myself singing along.
Rumor has it he's got a whole lot more up his sleeves, so consider me braced and ready for the next unexpected turn.