Ar tonelico
The Third Tower "Harvestasha", located in the region of Sol Cluster, was built to shoot the XP Shell into the Planetary in order to carry out the AAA Planet Regeneration Project, but due to several incidents that led it to lack the power necessary to finish its construction, it wasn't completed until near the end of the story of "Ar tonelico Qoga". The Third Tower itself doesn't have the functions of a Song Server, but it isn't linked to the First Tower like the Second is. The Song Server proper that houses the Soulspaces of the Sol Cluster Reyvateils is instead stored in the "Tower of Origin" located at Archia.