Two favorite programs of my childhood:

  10 REM drawing a galaxy
  20 FOR r=1 to 50
  30 CIRCLE 150, 100, r
  40 NEXT r
  50 ...


  10 REM playing a song
  20 BEEP 1,0: BEEP 1,2: BEEP .5,3: BEEP.5,2: BEEP 1,0
  30 ...