; ...

"Hello, world!"
(display "Hello, world!\n")
(format #f "Hello, world")

; Expressions are things that get evaluated when you execute a
; command.  Many expressions involve math. In math expressions
; operators MUST be delimited by spaces:

(+ 1 (* 2 3))

; ...

(* (+ 1 2) 3)

; ...

(begin (display "my key number: ") (between 60 90))
(format #f "my key number: ~S" (between 60 90))

; ...

; Errors: when you execute somethin that contains a mistake you will
; see an error message printed in the Console window. Sometimes this
; message is helpful, sometimes its not so useful. Such is life.  Many
; mistakes involve syntax errors or undefined terms as shown in these
; two examples:

(+ 1 (* 2 3) ; ?

(display foo)

; ...

(let* ((root (between 60 90))
       (third (+ root (pick 3 4)))
       (fifth (+ root 7)))
  (display "My random chord: ")
  (display (note (list root third fifth)))
  (newline))