Column 1.  This lists the record company of each recording and the number of the first known issue.  Where this is not known, I have listed possible candidates in numerical order.  I have also included details of recordings made but never released where that recording represents the only known recording of that work by a particular group or artist for a particular label.  These are indicated by “rej.” (for “rejected”) after the company name.  Although rejected records were never commercially issued, test pressings may exist in some cases.