The second developmental phase of the Online Chopin Variorum Edition is funded by the Andrew W Mellon Foundation and will run from October 2011 to March 2014, following a pilot study (May 2003 to October 2004) and a first developmental phase (November 2005 to September 2009). As at previous stages, the principal aim in this phase of research is to facilitate and enhance comparative analyses of disparate types of source material. By significantly increasing the digital content (in terms of both musical material and metadata) and by providing enhanced tools for its use, the second developmental phase will result in a considerably expanded resource of commensurately greater value to a range of musical and musicological communities. The research will exploit emerging technical capabilities for text/image comparison as well as recent musicological advances in cognate projects. The end result will be an altogether new type of 'dynamic edition'. Users themselves will be able to construct unique 'editions' of their own, combining elements from the digitised source materials with reference to the scholarly apparatus that will be provided. In addition, there will be tools for adding personal annotations and thus for creating highly flexible 'critical commentaries'.