Maybe it will help you
Transfer Music from an iPod to your Mac
1.Download and install Senuti.
2.Open Senuti and familiarize yourself with its interface.
3.From the Senuti menu, select Preferences. Select Copying.
4.Connect the iPod to your Mac if you haven't already done so.
5.In the Source side-bar, click Library. Unlike iTunes, Senuti uses Library to refer to your iPod's collection of music. After you click Library, you should see the songs on your iPod.
6.Select the songs you want to copy to your Mac.
7.Click the Copy button in the upper right-hand corner of the screen. Senuti will move the music from the iPod to your Mac.
I found this step by step guide explains "
how to transfer or backup music from iPod to Mac".
Hope that helped.