Hello,
calculating the average is not good for the must-hear criterion.
Let’s say 17 magazines give it an 80, two give it a 100, and Fantano gives it a 20 (because of its extreme ratings), then the album only has an average of 79.
You see, 19 have rated 80 or higher (so the majority thinks it’s must-hear), but it’s still not a must hear album.
You’d better use the median.