playing a chord in python

Question

I want to do make a platform to play chords like guitar does. For example - to play the E chord it playes [0, 2, 2, 1, 0, 0] (from the Low-E string to the High-E string).

I'm trying to play chords on python by playing all the different strings simultaneously (by using threads).

The problem is that every time I start playing the next strings, it seems that the last string stops playing, and that the new one replaces it. So all I hear after playing a chord is the highest string (the last one).

Do I use the threads not correctly? Or is it a problem with the current functions? Or maybe it's the winsound.Beep() function that canwt handle these kind of things?

This is my code:

from winsound import Beep
import threading
import time


def play(freq, dur):
    Beep(round(freq), round(dur))


def get_freq(string, fret):
    a3_freq = 220
    half_tone = 2 ** (1 / 12)

    higher_from_a3_by = 5 * (string - 2) + fret
    if string > 4:
        higher_from_a3_by += 1
    return a3_freq * half_tone ** higher_from_a3_by


def strum(string, fret, time):
    freq = get_freq(string, fret)
    t = threading.Thread(target=play, args=(freq, time))
    t.start()
    return t


def chord(frets, dur):
    threads = []
    for i in range(6):
        if frets[i] != -1:
            threads.append(strum(i + 1, frets[i], dur))
    for t in threads:
        t.join()


chord((-1, 0, 2, 2, 2, 0), 1000) # plays the A chord for one second, for example.

From what I've cheacked, the play() and get_freq() functions donwt have any problem.

So what is the problem, and how can I fix it?

Edit:

I've tried it in C# but it didn't work either. Is this the right way of starting threads in C#?

foreach (Thread t in threads)
    t.Start();
foreach (Thread t in threads)
    t.Join();

Answer 1

Gevent would make this much easier. Though still technically single threaded, context switching is so fast it would make it appear simultaneous. You can even use GIPC for multithreaded bi-directional multiprocess communication.

However I think your problem is much simpler. Your issue is the windsound module. Beep is not asynchoronous. So that is your limitation. You need to use

winsound.SND_ASYNC

This will allow you to send multiple events to play simultaneously.