Meh.

Linking music tastes and intelligence is really, really, wrong. What kind of music you like depends on so many factors, mostly environmental but... anyway.

Let's take a look at the article:

Mr Cadwallader then held an online discussion involving 19 members of the academy, 17 of whom were heavy metal fans.

Translation: Some psychologist asked some kids what kind of music they liked and they answered heavy metal. Oh and they also weren't complete idiots.
Since the sample was so big (almost 20 people!), obviously all "gifted" (definition?) children must listen to heavy metal. But since most of heavy metal is crap, he couldn't help but wonder why did these kids listen to this kind of crap.

One student said: "It helps me with stress. It's the general thrashiness of it. You can't really jump your anger into the floor and listen to your music at the same time with other types of music."

Ah! That makes sense, because smart people worry about society and stuff. The psychologist thought that his findings were so great he had to share them with the rest of the world, but he needed some statistics, so on his way home he asked some more kids about what kind of music they liked so he can make useless statistics that help make a research look all that much more professional:

The researchers surveyed 1,057 members of the National Academy for Gifted and Talented Youth - a body whose 120,000 student members are within the top five per cent academically in the 11-19 age range. Asked for their favourite type of music, 39 per cent said rock, 18 per cent R&B and 14 per cent pop. Six per cent said heavy metal and a third rated it in their top five genres.

Okay so he found that from a group of supposedly smart kids (although I'm not sure that academia equals intelligence), SIX percent really likes bands like tool, slipknot and system of a down (which are very popular bands anyway) and about one third said "tool? they're cool, I used to listen to aenima a lot". Did that miniscule percentage surprise him that much that he had to go and tell the world?