As of the next version gmpc-glyros will be a intern plugin of gmpc.
The code here is only for future reference, and/or for older versions of gmpc.
(Not guarantee that they’ll work!)

A plugin for the popular Gnome Music Player Client (gmpc), using the unknown and infamous libglyr library
to fetch reliable all sort of metadata, including lyrics, cover, artist photo, album reviews, artist bio and similar artists and songs.

There is a PKGBUILD for Archlinux available, user’s of other distribution may build from Source:

• Install libglyr first
• Make sure you have the gmpc-headers installed.
• git clone https://github.com/sahib/gmpc-glyros
• cd gmpc-glyros
• cmake . -DCMAKE_INSTALL_PREFIX=/usr
• make
• sudo make install
• Load up gmpc and make sure it’s checked in the Preferences dialog.
• Optionally disable other lyrics and cover providers there.