There has been no official word that Logic Studio will run on Leopard unless you count the Logic Pro specs which requires Mac OS X v10.4.9 or later. However, we have heard positive results from Logic Pro running on early developer versions of Leopard.
Category: Software Updates
GarageBand 4.0.1 Update
This update fixes minor problems with Magic GarageBand, some graphic display issues, compatibility with 3rd party software, and general compatibility issues. You’ll need to download the iLife Support 8.1 update first.