If you are using external devices or folders (other than "Music") to synchronise music to your phone, you have to enable access on a Mac software. To do this, go to File > Allow Access to Folder.
- Windows Phone app for Mac will not sync music on my Lumia phone. What should I do?
- How do I create a music playlist on my Lumia (Windows Phone 7)?
- How can I transfer my contacts, messages, calendar entries or photos to my Lumia?
- Audio quality is poor when I listen to music using Bluetooth
- Can I play music files from my Lumia phone on my car stereo system?