Share the finished GarageBand song to iTunes and sync the iPad with your mac. Then you can sync the song from iTunes on your Mac to the Music.app on the iPad. See this help page: http://help.apple.com/garageband/ipad/2.0/index.html#chs39284d66
- Tap My Songs, then tap Select.
- Tap the song you want to send, then tap the Action button
.
- Tap Share Song via iTunes.
- Do one of the following:
- To send the song as a GarageBand song, tap GarageBand.
- To send the song as an audio file, tap iTunes, then tap Share.
After you tap the iTunes icon, you can choose the quality of the file GarageBand sends to iTunes. You can also add artist, composer, and title information that appears in iTunes.
- Sync your iPad with your computer.In iTunes, the exported song appears in the Documents list in the File Sharing area when GarageBand is selected.
- Do one of the following:
- Drag the song from the GarageBand Documents list to the Finder.
- Click Save As, navigate to the location where you want to save the song, then click Save.
You can open the GarageBand song in GarageBand on your Mac, or play the audio file in iTunes (or any compatible audio application) on your computer. GarageBand songs cannot be opened on a Windows computer.
You could also mail the song to your mac,
- Tap My Songs, then tap the Action button
.
- Tap Share Song via Mail.
- Enter the artist, composer, and album name if you wish, then tap Email.An email message appears, with the song as an attachment in AAC format.
- Tap the To, Cc/Bcc, and Subject fields to edit the recipients and the subject of the email. To choose recipients from your Address Book, tap the Add Recipient button.
- Tap the body of the email to edit the message text.
- When the email is ready, tap Send in the upper-right corner to send it.You can’t send the email until you add at least one recipient.