Go to 'Applications' > 'iTunes Service' under the tab 'General' enable the iTunes Service by ticking the checkbox says 'Enabled iTunes Service'. You can configure the service to require the authentication by entering a password here too. Depending on the language of your file names you can select the correct language encoding that matches it. Click on 'Apply' to proceed and that's all you need to do on the QNAP NAS.

By default the iTunes service on QNAP scans all the music files stored under Qmultimedia folder therefore you can start transferring all your music files to this share through Windows mapped drive or FTP now.

Connect the PC and QNAP Turbo Station to the same LAN and start iTunes on your PC. You should see an entry (your NAS name generally) shown under 'SHARED' subsection on the left panel of iTunes interface (TS-219-Pro in this example). Click on the NAS name and it will bring up a list of all the music files stored under Qmultimedia and they are ready for playing right away.

This function is very useful. You can save the mp3 files on Turbo Station instead of different computers at home, and then play the files on Turbo Station by iTunes player by any computer in streaming way.

Digital Media Player devices e.g. Roku's Sound Bridge, have become increasingly popular recently. Some of these devices start to support music playback from iTunes on the same network. You can use these devices to play the mp3 files on Turbo Station without turning on the computer. (see illustration below)

Conclusion
With the iTunes Server provided by Turbo Station, you can save mp3 files collectively and share the files on LAN. You can play the files by iTunes installed on any computer. Moreover, Turbo Station's energy-saving, fanless, and aluminum alloy case design enable absolutely silent and stable performance. It is an ideal choice for home and small office.