lots of memory, won't sync to iPod

downloaded new discs to my iTunes music library and for the first time am getting an error message that there is not enough free space on my iPod touch which is 32

my iPod says I've got 26.9 GB in music available.

I tried to sync through my computer, I tried to sync through the iPod

I erased 4 audio books,

I don't know what else to do - I pay for 50 GM storage and it's a 32 GB iPod.

Can you help? Do I need to erase more. I have no photo library on this device.

What can I do?