Transfer music from iPad to Mac?

use the migration assistant to move your data over

Try this: http://www.ipadtomactransfer.org/

iTunes includes an option to transfer iTunes content that was purchased/downloaded from the iTunes store from an iPod, iPhone, or iPad.
With the iPad connected, at the iTunes menu bar go to File and select transfer purchases from - the name of your iPad.
Related Guides:
http://www.iphone-mac.com/how-to-transfer-ipad-music-video-from-ipad-to-mac.html
http://www.iphone-mac.com/how-to-transfer-and-copy-music-songs-from-ipad-to-pc.html

Try this http://www.fadingred.com/senuti/

Need to recover music, playlists, or videos from your iPod or iPhone? Look no further! With Senuti, you can recreate your iTunes music library in just one click. Want to be more specific? Preview and select only the songs and playlists you want to transfer. One Step Recovery

Take a shortcut and recover all your music, playlists, 
and videos to iTunes in one step.

Song Preview

Preview any song before you transfer — just push play.
iTunes Comparison

Senuti automatically compares all the songs on your iPod or iPhone to your computer's iTunes library. Any song that is already on your computer will be marked with a blue dot.
Playlist Transfer

With a simple drag and drop motion, transfer specific playlists directly from your iPod to iTunes on your computer.
Video Transfer

On the iPod and iPhone, videos work just like songs — so they will show up and transfer in Senuti with your music.