You need to pay SimCash or real money for it im not sure if The cash or money.you just need to pay for it
anoymous
Save them cash until you can unlock it with that.
anoymous
You must wait until you obtain the (rare) piano skill heirloom from a retiring sim! It can take a while, but that's what needs to happen to unlock the rest of the items you'll require for the piano hobby (which once unlocked will be available for purchase in the store)