Possible Clues:

• It's what Barry and Gary do
• 'I'm tired of love: I'm still more tired of -' (Belloc)
• Samuel Butler saw it as 'the rudder of verses'
• Free verse lack
• Word for bird
• What good rap will do
• Poem may lack this, and reason too?
• Dr. Seuss forte
• Versification (which goes with reason)
• Conventional pen Miss Taylor kept from editor