IMSLP is currently in a collaboration with the Piano Society by mutual linking of score/recording pages. This page is a How-to guide on how to link from IMSLP to Piano Society.
Since IMSLP v0.3 both the Composer and Work (Description) template support the parameter "|Recordings=". You may simply use this parameter to add links to external recording sites, which in this case would be the Piano Society. An example can be found on the J.S. Bach page.
While normally we could just use a plain link, for future flexibility and customization a template has been set up: {{ps}}. To use this template, simply add the number in the Piano Society URL after "section=" to the template, in the form {{ps|xxxx}}, where xxxx is the number.
For example, to link to the following Piano Society page:
http://pianosociety.com/cms/index.php?section=21
You can simply do this:
{{ps|21}}
At the beginning of this collaboration the Composer templates should be linked first; the Work (Description) templates can come later.