I've just finished Haruki Murakami's 'After Dark' - highly recommended.

It contains a definition by an amateur musician of what is required to 'play really creatively' :

"You send the music deep into your heart so that it makes your body undergo a kind of physical shift, and simultaneously the listener's body also undergoes the same kind of physical shift. It's giving birth to that kind of shared state ...".

As a listener, and non-musician, I'd be interested to know if this resonates with any musicians out there. It pains me to admit that I could indentify maybe only three or four pieces of music that, for me, consistently produce that kind of physical reaction:

Blue Nile - 'Saturday Night'
Van Morrison - 'Rave On John Donne'(from Live At The Grand Opera House)
Rick Danko - 'It Makes No Difference' (from The Last Waltz
John Martyn - 'Solid Air'