http://support.apple.com/en-us/HT200269 MainStage 3.1 includes the following changes. For more information, see http://www.apple.com/logicpro/mainstage. New Features and Enhancements * Redesigned Compressor plug-in with scalable, Retina-ready interface and a new compressor model. * Retro Synth can now create wavetables from imported audio and is able to stack up to 8 voices. * The Plug-in Manager now allows you to customize the organization of your menu. * Expanded sound library includes over 200 new synth patches and 10 Mellotron instruments. * New Auto Sampler plug-in converts hardware synthesizers into sampled instruments. * Custom shortcuts can be assigned and managed using the new Key Command editor. * It is now possible to copy and paste ranges in the layer editor.