Play sinusoids with pygame/numpy

tonegen.py

import pygame
import numpy as np
from pprint import pprint
import time
import math

notes = {
	'g3':196.00,
	'gs3':207.65,
	'a3':220.00,
	'as3':233.08,
	'b3':246.94,
	'c4': 261.63,
	'cs4': 277.18,
	'd4': 293.66,
	'ds4': 311.13,
	'e4': 329.63,
	'f4': 349.23,
	'fs4': 369.99,
	'g4': 392.00,
	'gs4': 415.30,
	'a4': 440.00,
	'as4': 466.16,
	'b4': 493.88,
	'c5': 523.25,
	'cs5': 554.37,
	'd5': 587.33,
	'ds5': 622.25,
	'e5': 659.25,
	'f5': 698.46,
	'fs5': 739.99,
	'g5': 783.99,
	'gs5': 830.61,
	'a5': 880.00,
	'as5': 932.33,
	'b5': 987.77,
	'c6': 1046.50
}

def getSound(freq=261.63):
	length = np.int(np.ceil(48000/freq))
	samples = np.zeros(length, dtype=np.int16)
	for i in range(0,length):
		samples[i] = np.uint16((32768/4)*np.sin(i*2*np.pi*(freq/48000)))
	sound = pygame.mixer.Sound(samples)
	return sound
	
pygame.mixer.init(48000, 16, 1, 1024)

sounds = {}
for k, v in notes.items():
	sounds[k] = getSound(freq=v)
	
print("Starting")

series = ['c4', 'e4', 'g5', 'b5', 'g4', 'b4', 'd5', 'f4', 'as4', 'd4', 'f5', 'a3', 'c4', '', '', '', '']
j = 0
duration = 0.5
for i,s in enumerate(series):
	if not s == '':
		print("Starting " + str(i))
		sounds[s].play(loops=-1)
	if i > 2:
		print("Stopping " + str(j))
		sounds[series[j]].stop()
		j += 1
	time.sleep(duration)