How to Make Music Available without Wi-Fi on Your Nexus 7
Because Google made it a pain to copy music to your Nexus 7 from your PC, the music is not available full time because most of the music stored on the tablet is from the Internet. As long as you have a Wi-Fi connection on your Nexus 7, the music plays. When you don’t have a connection, the music doesn’t, either. That is, unless you follow these steps:
Locate the song, artist, or album you want to keep stored on the tablet.
Touch the Menu button to the right of the song, artist, or album.
Choose the Keep on Device command.
The Nexus 7 ensures that the music is transferred to the tablet from the Internet and therefore is available to play all the time.
A quick way to select multiple songs, albums, or artists for download from the Internet is to touch the Menu icon button and choose the command Choose On-Device Music. Touch the push-pin icon next to the songs you want to keep on the tablet. Touch the check mark button (in the lower-left area of the screen) when you’re done.
If you want to see which songs are available on the device, touch the Menu icon button and choose the On Device Only option. After doing so, only the music copied to your Nexus 7 appears in the Play Music app. Choose the On Device Only command again to see all your music, stored locally (on the Nexus 7’s internal storage) or online.