'Phoenix the Rapper' on The Late Show with David Letterman

Phoenix was definitely acting weird in his appearance on The Late Show, which seemed to unnerve Letterman. Q: Was Letterman punked?

I'm also starting to think that Joaquin Rafael Phoenix -- who in my opinion is one of today's greatest actors -- has taken his artcraft up a notch and is now producer, writer, actor of a performance that merges reality and fiction, happens across all media forms and venues, and obliterates the 90 minute timeframe.

In the process, is he careening to the edge of madness?