beer song implemented (nearly) as a single FORMAT statement.

gistfile1.lisp

(defun verse (start &optional (end start))
  (format nil
          "~:{~[~

No more bottles of beer on the wall, ~
no more bottles of beer.~%~
Go to the store and buy some more, ~
99 bottles of beer on the wall.~%~%~

~:;~

~:*~d bottle~:p of beer on the wall, ~
~:*~d bottle~:p of beer.~%~
Take ~[it~:;one~] down and pass it around, ~
~:*~[no more bottles~:;~:*~d bottle~:p~] of beer on the wall.~%~

~]~v%~}"
          (loop for i from start downto end
             collecting (list i (1- i)
                              (when (= start end) 0)))))

(defun sing (start &optional (end 0))
  (verse start end))