You will have to forgive me, but i can't find a reason why your band didn't wrote new song. Nothing in logs. And several new songs were written today for other bands.
Can you try next time to write new song for 1 turn?
Also, as you start to get some money, it's usually better to create a new band. It probably will bring more action into game for you, and you will not have to wait so long to do something.