Maybe someone found it useful. Most of solutions here propose a music server as music files storage with a possibility to stream its content to any local and possibly an external machine. I use a little different solution. All music get stored on a big (1Tb or more) drive connected to Raspberry Pi. The machine gets connected to a receiver using HDMI, or any other DAC as in the review of Allo Boss Raspberry Pi DAC. A music player runs on Raspberry Pi and can be controlled by web interface on a mobile phone or any other computer. I found such solution very convenient for a small apartment or flat.