Conversation so far:
What started musician John Butler's solo career?
John Butler gave a live solo performance at Twist and Shout Records in Denver, Colorado, which was released in 2008 as an eight-track EP, One Small Step.
Was the One Small Step EP by musician John Butler well received?
Did musician John Butler tour during his solo career?
In July 2009, John Butler undertook a solo overseas tour commencing in North America.
How did musician John Butler's solo overseas tour do?
How many shows did musician John Butler do during his overseas tour?
Did musician John Butler ever collaborate with anyone of note?
John Butler performed Funky Tonight in a collaboration with fellow Australian musician Keith Urban.
Was there any controversy during musician John Butler's solo career?

Question: Who influenced his solo career?
Self-contained rewrite: Who influenced musician John Butler's solo career?