" 
 : A couple of comments. The information is sourced, as given, from a presumably well-researched Gould biography. Undoubtedly the album has sold many more copies since his death, and those figures are ""as of"", and times have changed in the music industry. I'm not sure it's meaningful to compare sales of this album in a 20-year span ending before the artist's death with the entire catalog of a top conductor. I agree that the numbers could be wrong, but the answer is to find other information. You are welcome to edit ""astonishing"" (a quote from the source) to simply ""high"", for example.   "