Yes, you can.
One PIN code can be used to download the music on more devices. So you can download the music into your Sonorias app in all the device you have. This is good especially when you are travelling or when your kids need to listen. One day they can listen from mother phone, next day from fathers phone and another day from the home tablet.
You need to keep in mind that if you downloaded the music into more devices, you will need to download the new music again to all devices to avoid listening of the old music. We will try to update the mobile apps to keep you updated and keep all mobile apps in sync, but for now you need to do it manually.