Take your top 20 artists. For each of these artists, collect the top 5 similar artists. The resulting number of unique artists is your [b]eclectic score[/b]. If the score is small (extreme = 5) your musical preferences are very limited, and if it is large (larger than 80, extreme = 100), then you have an eclectic musical preference.
You can compute your own score at http://anthony.liekens.net/pub/scripts/last.fm/eclectic.php
jameslebyrne's eclectic score is
If your score is small (lower than 70) your musical preferences are very limited, and if it is large (larger than 80), then you have an eclectic musical preference.
jameslebyrne's super-eclectic score is
As this number is larger, you have a more eclectic musical preference. People with scores over 700 have bragging rights. People whose score is below 400 should consider more musical styles!