Install python3 on the Raspberry

sudo apt-get install python3

Install python3 RPi GPIO library

sudo apt-get install python3-rpi.gpio

 Download https://github.com/mxgxw/MFRC522-python 

then replace print "" by print("") to make it suitable for python3

sudo python3 setup.py install

 sudo apt-get install mpd

configure

/etc/mpd.conf

group "audio"
auto_update "yes"

audio_output {
        type            "alsa"
        name            "USB"
        device          "hw:0,0"        # optional

sudo raspi-config

 Interfacing options -> SPI enabled

Alsa is the sound infrastructure. We need to tell it to use the USB Sound card:

/etc/modprobe.d/alsa-base.conf

# This sets the index value of the cards but doesn't reorder.
options snd_usb_audio index=0
options snd_bcm2835 index=1

# Does the reordering.
options snd slots=snd_usb_audio,snd_bcm2835

Install Samba to make the Raspi available as a windows share

sudo apt-get update
sudo apt-get install samba samba-common-bin

 create the share directories (you can also use an USB Stick as storage)

mkdir /media/music
mkdir /media/playlists

add them to the samba config to be available on the network

sudo nano /etc/samba/smb.conf

add

[playlists]
Comment = Playlist files
Path = /media/playlists
Browseable = yes
Writeable = Yes
only guest = no
create mask = 0777
directory mask = 0777
Public = yes
Guest ok = yes

[music]
Comment = music files
Path = /media/music
Browseable = yes
Writeable = Yes
only guest = no
create mask = 0777
directory mask = 0777
Public = yes
Guest ok = yes

set a samba password

ududo smbpasswd -a pi

restart samba

sudo /etc/init.d/samba restart

Now you can add playlists and music files via network 

We want our player to start right after booting, so

crontab -e

add

@reboot python3 /home/pi/pyJukebox/pyJukebox.py &

 the path might vary, depending on where you've put the python files.