Never gonna beep you up.

ricknroll.py

from RPi import GPIO
import time

mid = 440/(2**(10/12))
notes = dict(zip("C C# D D# E F F# G G# A A# B".split(), [mid*2**(i/12) for i in range(12)]))
speed = 60/114

scores = [
  (-1, "A", 1/4),
  (-1, "B", 1/4),
  ( 0, "D", 1/4),
  (-1, "B", 1/4),
  ( 0, "F#", 3/4),
  ( 0, "F#", 3/4),
  ( 0, "E", 3/2),

  (-1, "A", 1/4),
  (-1, "B", 1/4),
  ( 0, "D", 1/4),
  (-1, "B", 1/4),
  ( 0, "E", 3/4),
  ( 0, "E", 3/4),
  ( 0, "D", 3/4),
  ( 0, "C#", 1/4),
  ( -1, "B", 1/2),

  (-1, "A", 1/4),
  (-1, "B", 1/4),
  ( 0, "D", 1/4),
  (-1, "B", 1/4),
  ( 0, "D", 1),
  ( 0, "E", 1/2),
  ( 0, "C#", 3/4),
  (-1, "A", 1),
  (-1, "A", 1/2),
  ( 0, "E", 1),
  ( 0, "D", 2),

  (-1, "A", 1/4),
  (-1, "B", 1/4),
  ( 0, "D", 1/4),
  (-1, "B", 1/4),
  ( 0, "F#", 3/4),
  ( 0, "F#", 3/4),
  ( 0, "E", 3/2),

  (-1, "A", 1/4),
  (-1, "B", 1/4),
  ( 0, "D", 1/4),
  (-1, "B", 1/4),
  ( 0, "A", 3/4),
  ( 0, "C#", 3/4),
  ( 0, "D", 3/4),
  ( 0, "C#", 1/4),
  ( -1, "B", 1/2),

  (-1, "A", 1/4),
  (-1, "B", 1/4),
  ( 0, "D", 1/4),
  (-1, "B", 1/4),
  ( 0, "D", 1),
  ( 0, "E", 1/2),
  ( 0, "C#", 3/4),
  (-1, "A", 1),
  (-1, "A", 1/2),
  ( 0, "E", 1),
  ( 0, "D", 2),
]

print(notes)
print(scores)

GPIO.setmode(GPIO.BCM)
GPIO.setup(18, GPIO.OUT, initial=GPIO.HIGH)

buzz = GPIO.PWM(18, 440)
buzz.start(99)

for o, n, l in scores:
  buzz.ChangeDutyCycle(99)
  buzz.ChangeFrequency(notes[n]*(2**(o+1)))
  time.sleep(speed*l)
  buzz.ChangeDutyCycle(0)
  time.sleep(0.01)

buzz.stop()
GPIO.output(18, GPIO.HIGH)
GPIO.cleanup()