Streaming Music Over Internet

I have set up my WD My Book Live to stream music to iTunes.  It works flawlessly on my iPhone using the wd2go app.  On my MacBook Air it also works just fine over the LAN.  When I start iTunes, it recognizes and mounts My Book Live as a shared device with no problems.  But when I try to stream music over the internet from wd2go.com on my MacBook Air, iTune launches and the music file is physically downloaded to the HD.  Why can’t music simply stream to my MacBook Air (like it does to my iPhone)? 

maybe you need to UNCHECK “copy files to iTunes media folder when adding to library” or smth…