Add functionalities to Magento store

I'm on the way to build a digital music store with Magento platform. I have no problem installing the platform and customizing a theme, but I need to integrate the store with some advanced functions. Basically, I need to sell digital music. I can sell single tracks but I also can sell albums (means something like grouped products) with a price that obviosuly will be the total of the tracks with a discount (or a specific price). Seems like Magento does not allow to assign a price to a grouped product, and so I dont know what to do.