If Melodyne is not showing up inside of Studio One 4, please uninstall the program and re-install. When re-installing, be sure to install the 64-bit version. If you are on Windows, make sure that you install the 64-bit version to the c:\Program Files...directory and not to the c:\Program Files (x86)...folder. If you are having a problem with the UI inside of Studio One, make sure that you keep the Melodyne window docked. You will want to check future release notes to see if the UI issue has been resolved.