Take your top 20 artists. For each of these artists, collect the top 5 similar artists. The resulting number of unique artists is your eclectic score. If the score is small (extreme = 5) your musical preferences are very limited, and if it is large (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
My eclectic score is currently
88/100
The 88 related artists for my profile are adiemus alanis morissette anathema anna ternheim bad boys blue bee gees björk (2) black sabbath blondie (2) bo kaspers orkester bob dylan…