Hitmaker Max Martin back with Taylor Swift for 'Showgirl'

For her much-awaited new album "The Life of a Showgirl," Taylor Swift reunited with Swedish producer Max Martin, who revolutionized modern pop with a formula that blends technology, simplicity -- and a feel for the perfect hook.

At first glance, Martin looks more suited to work with heavy metal bands than pop icons.

Indeed, the career of the long-haired, bearded musician clad in black started in metal and hard rock.

Martin -- born Karl Martin Sandberg in the Stockholm suburb of Stenhamra -- entered the music scene in the 1980s as a singer for the band It's Alive which, he says, took inspiration from Metallica, KISS and Def Leppard.

In the early 1990s, he pivoted to work more in songwriting and production, quickly making a mark with global hits for Swedish groups Ace of Base and Army of