Each time a listener reviews a song, their answers to the confidential
review questions
are incorporated into a formula that generates the five-star display.
This is the same
formula that generates the Garageband charts.
However, unlike the chart ranking, the
five-star display is less dependent on how many other songs are in the
chart: for example,
an average song might be ranked #50 out of 100 or #500 out of 1,000, but
would get 3.0
stars regardless.
Furthermore, while a song may
"climb" up the chart as it receives its
initial reviews and qualifies for higher rounds of the contest, the
five-star display is
designed to be a more consistent indicator of a song's overall
performance.
The five-star
display is graded on a steep curve: almost 65% of songs receive 2.5 -
3.5 stars, and only
the top 1% of songs receive more than 4.5 stars.