Bookworld is offering 15% off CDs on top of their usual 5% off for citizens. Can't see any information about how long it's valid for.
Note: No code is required - listing prices are pre-15% discount, and you'll see it applied in your shopping basket.
"Citizenship" is just their name for registered users - registration is free. Citizens get 10% off books and 5% off CDs.
They have a good selection of classical and jazz CDs and prices are usually very competitive even before the extra discount. I quite often use them for CDs that are hard to find in Australia.
Starthere members can also get 3.5-6.3% cashback now.
I can confirm this is working. Prices are listed as normal, but the additional discount is automatically calculated (as if it were a coupon code) when you add an item to your shopping cart. No code required.