Announcing ClearScale: Open Source Commercial-Grade Time Stretching/Pitch Shifting Project ClearScale is an open source GPL-based project to bring high quality time stretching and pitch shifting to the Linux platform. The goal is to create an open standard for a commercial grade algorithm that allows changing the pitch and speed of music and sound independently of each other. It should achieve this in an artifact-free, sonically pleasing manner, comparable to commercial algorithms on the MacOS and Windows platform available today. The algorithm should work equally well with musically monophonic and polyphonic material over a wide range of scaling ratios, and it should encompass a way to compensate for the formant shifts ("Mickey-Mouse effect") that occur during pitch shifting. It is hoped that an open standard for such an immensely important integral part of audio processing will make Linux-based audio processing both easier and more popular. The algorithm should be designed to serve as a quality reference for other algorithms in the field, and a suite of audio files and test signals will be provided with it to serve as a testbed for other future algorithm designs. The project is initiated by Stephan M. Bernsee (formerly Stephan M. Sprenger) who maintains a highly popular educational web site about time stretching and pitch shifting and related topics at http://www.dspdimension.com. He has authored several commercial solutions on the MacOS and Windows platform and his papers and algorithms are part of lectures on DSP at several universities and online courses. The project has initially been funded by a private research grant and its running costs will be financed through PayPal donations to its maintainer. More information on its current status, design goals and a FAQ can be found on the project web site, http://www.clearscale.org