If you are a registered owner of any previous version of Reason, you are eligible to purchase this upgrade version. Stronger, swifter and smoother to work with, Reason 4 will alter the way you create your music. Reason's new devices and features will not only inspire you to produce great tracks, they will provide you with new ways of doing so. If you're already a Reason user, trying out Reason 4 will most likely stun you like you haven't been stunned since your first Reason encounter. The Thor polysonic synthesizer features six different oscillator types and four unique filters, as well as an all-powerful modulation matrix gives you complete control over your signal flow, letting you modulate anything within Thor with anything within Thor. Reason 4 ships with RPG-8, a brand new unit dedicated to the art of arpeggiation, and the ReGroove mixer, Reason's own realtime groove management device. The new sequencer is swifter, stronger and more intuitive than ever, and comes with new features and functions that all strive toward making your Reason experience smoother and snappier. Also new to Reason 4 is the new Tools Window, a floating window containing all your most frequently used tools. Requires Windows XP or Vista, or Mac v. 10.4, as well as a previously installed copy of Reason 3. Four different language versions - English, French, German or Japanese Sound Bank holds patches for all devices in Reason to help New Tools Window holds all your most frequently used tools Combinator & NN-XT updates Windows requirements - either Windows XP or Vista, Intel P4 / AMD Athlon XP or better processor Mac requirements - Mac OS X 10.4, G4 1GHz and up or Intel Mac processor