because your music is saved on the old computer. You are logging in to your iTunes store account so you can continue to purchase music. This is separate from the music you already have in your iTunes library. you will need to copy your existing music library from the old computer to the new computer to access it with the new iTunes software.
Download music legally and download iTunes onto your computer!!
Download iTunes
if you can access itunes on your phone you can download music through there ,but if not you can use itunes on your computer , download them through there and synchronise your iphone with your computer.
itunes
You can download it on iTunes.
sync you Iphone with your Itunes library.
Itunes. You can download it from itunes.com
Download to computer. Import into iTunes, sync iPad.
Download iTunes on a computer that has an SD card slot. Put music onto iTunes. plug the sd card in and drag the music onto it
If you search google, and download Sharepod or iDump you can transfer music from your iPod to your computer then onto iTunes. These are both free software.
you put itunes on your computer or laptop, not the ipod itself. Then use itunes to download the music to your ipod. If you go on the apple website it has quite simple instructions on how to download itunes and music.
Open iTunes on your computer and click on iTunes store