Can't play multiple .mp3 files in streaming function using Shouty

I’m writing some code that connects to an IceCast server using Shouty. My code takes an .mp3 file and streams it using IceCast to a web player I made.

from multiprocessing import Process, JoinableQueue
import queue
import subprocess
import os

from flask import Response
import shouty

class Worker(Process):
    def __init__(self):
        super().__init__()
        self.queue = JoinableQueue()
        self.is_mp3 = True

    def put_queue(self, mp3file):
        self.queue.put(mp3file)

    def join_queue(self):
        self.queue.join()

    def checkMP3(self):
    ''' Check files before streaming'''

    def go_Stream(self):
        with shouty.connect(**params) as connection:
            song_path = 0
            allfiles = os.listdir('app/')
            for i in allfiles:
                if i[:1] == "C":
                    song_path = i
                    return Response(self.streamStart(connection=connection, mp3file=song_path), mimetype="audio/mp3")

    def streamStart(self, connection, mp3file):
        with open('music/' + mp3file, 'rb') as song:
            ffmpeg = None
            src = song
            if self.is_mp3:
                ffmpeg = subprocess.Popen(
                    [   
                        "ffmpeg",
                        "-i",
                        "-",
                        "-f",
                        "mp3",
                        "-ab",
                        "192",
                        "-",
                    ],
                    stdin=song,
                    stdout=subprocess.PIPE,
                    stderr=subprocess.DEVNULL,
                )
                src = ffmpeg.stdout
            chunk_size = 4096
            sent_bytes = 0
            if src:
                while True:
                    chunk = src.read(chunk_size)
                    if not chunk:
                        return "Buffer Empty"
                    yield chunk
                    sent_bytes += len(chunk)
                src.close()
            if ffmpeg:
                ffmpeg.terminate()

    def run(self):
        checkMP3()

def run ():
    w = Worker()
    w.start()

In an HTML page I have set up with Flask, the web player has a play button that triggers go_Stream. It works, but it only plays one of the .mp3 files and I can’t figure out how to keep playing the .mp3 files in the directory. Should I have some loop in place that streamStart for every .mp3 file?