I've just started using the iTunes feature for music. I loaded 29 CDs into the iTunes library on my iMac and synced it with my iPhone5 and iPad4. The iPhone shows music storage usage of 1.8GB and the iPad 3.1GB for the exact same set of songs. Is the storage/compression code different on the two devices or have I missed something on the iPad that is causing it to use more memory than the iPhone? Both devices using latest iOS (6.1.4 for iPhone 6.1.3 iPad). The difference is significant enough to raise an eyebrow and after some searches on this site and elsewhere, I can't find an answer.