Hi Frank,
thanks for the tip. The group audio already existed but the second command did the trick concerning chown -R audio.mpd /mnt/MPD. But the only sign of life is nginx is running but needs to be configured on http://ip.address.
One question if I would like to install your mpd version with pipe out, do I need to uninstall the normal package first? And can I do this? Is your version pipe out only or can I choose between standard mpd and mpd with pipe?
Best Regards
Tinitus