This document contains keyboard shortcuts and modifier keys for Reason 4. It lists shortcuts for general functions like creating/opening songs, cutting/copying/pasting, and undo/redo. It also includes shortcuts for the rack, sequencer, and matrix. Shortcuts are provided to select/move devices and tracks, edit clips, quantize notes, join/merge clips, and zoom/scroll. Modifier keys allow functions like creating automation lanes, setting locators, limiting movement, and toggling tools.