content: -- This handler takes a script object (singer)
  -- with another handler (call).
  on sing about topic by singer
  	call of singer for "Of " & topic & " I sing"
  end sing
  
  -- Define a handler in a script object,
  -- then pass the script object.
  script cellos
  	on call for what
  		say what using "Cellos"
  	end call
  end script
  sing about "functional programming" by cellos
  
  -- Pass a different handler. This one is a closure
  -- that uses a variable (voice) from its context.
  on hire for voice
  	script
  		on call for what
  			say what using voice
  		end call
  	end script
  end hire
  sing about "closures" by (hire for "Pipe Organ")
  