This is an experimental beta feature, and is not fully supported or even guaranteed to remain part of muso. However, while it is there, please feel free to enjoy it, and add any feedback into the Discussion area. It's currently available only via the small icon in the top right corner of the main Muso window.
It is inspired by this microsoft control, I have tried to make the main features work in a similar way but for muso albums (minus the Back button support, this isn't available):
WIKI PAGE TO BE COMPLETED