You need iTUnes on your computer. Install it if you haven't already. You will need at least iTUnes 11 to sync with the iPad 4, so you may need to upgrade.
Import your music into iTunes
hook your iPad up to your computer and open iTunes
Choose what music to put onto your device
and you should be good to go.
Install the latest version of iTunes on your computer.
Start iTunes on your computer. Go to the view menu and select View > Show Sidebar.
Connect your iPad to your computer.
Select your iPad in the left column.
Select Music in the right side of iTunes.
Then make selections to either select all music or select the playlists you want on your iPad.
Then click on Apply or Sync in the lower right corner of iTunes.