I have two a suggestion. Firstly, don’t store your music files in the ‘/Public/Shared Music’ folder. Create your own dedicated music share for these files. The /Public/Shared folders are for Twonky media server. Refer to this post if you want more details http://community.wd.com/t5/WD-My-Cloud/FAQ-Twonky-DLNA-Media-Server-Setup-amp-Use/td-p/858810
Even if you are not using Twonky this may still cause some problems if you locate your files in that area.
Secondly, are you ripping your music directly to the MyCloud? Rip them to your computer then copy them over to the MyCloud later. This will avoid files dropping out if there are connectivity issues.
