Metronome program not running properly on Raspberry Pi 2

Question

I am new to python and I am trying to create a simple metronome program. When I run my program I am running into a problem where the audio does not sound evenly spread out. I am running this on a Raspberry Pi 2 Model B. I have also tried using sleep() and time.monotonic(), but I ran into the same problem. Does anyone know what is going on here?

import time
import pygame

path = ("/home/pi/Documents/Loop/")
sound_file = ["kick.wav"]
pygame.mixer.init()
pygame.mixer.music.load(path + sound_file)

BPM = 60
BPMS = 60/(4*BPM)
#Metronome plays on quarter notes


delay = BPMS
past = 0
note = 1

while True:
    now = time.perf_counter()
    if now >= past + delay:
        if note == 1:
            pygame.mixer.music.play()
        elif note == 2:
            pygame.mixer.music.play()
        elif note == 3:
            pygame.mixer.music.play()
        elif note == 4:
            pygame.mixer.music.play()

        past = now
        note = note + 1
        if note > 4:
            note = 1

Answer 1

When I initialize pygame with a buffer of 512 it seems to solve the problem: pygame.mixer.init(buffer=512)