Number Six is a family of fictional characters from the reimagined science fiction television series Battlestar Galactica. She is portrayed by Canadian actress and model Tricia Helfer. Of the twelve known Cylon models, she is the sixth of the "Significant Seven". Like the others of the "Significant Seven", there are several versions of her, including Caprica-Six, Shelly Godfrey, Gina Inviere, Natalie Faust, Lida, and Sonja. She is the only model that does not use one particular human alias for all copies. The character was named after Number Six, Patrick McGoohan's character from the show The Prisoner. Appearance and personality traits Throughout the show, Six is portrayed as a seductive, statuesque Cylon infiltrator. She was the first example shown of a new generation of Cylons capable of adapting to human form and emotions. Little else is known of her earlier years. She can, like other Cylons, retain memories which can be downloaded into another body if the original body is killed. Like her counterparts, her body was designed to mimic the human body at the cellular level, making her almost undetectable to testing procedures, and there are many copies of her in existence. Sixes and Eights are the Humanoid Cylon models shown most frequently. Sixes tend to have individualistic traits and are considerably susceptible to the full array of human emotions. Although extremely effective and adaptive, Sixes always show a certain disdain for their given chores and dislike being treated as expendable. Most versions of Six have platinum-blonde hair, including Caprica-Six, Shelly Godfrey and Sonja. Others such as Gina Inviere, Natalie Faust and Lida have honey-blonde hair, and one Six with black hair has been observed. It was stated by Caprica showrunner Kevin Murphy that had the prequel series Caprica continued, it would be revealed that the Sixes' default personality was modeled after that of Zoe Graystone. Music Since her debut in the mini-series, a leitmotif has been used in scenes featuring Tricia Helfer as Six. This simple 8-note motif was composed by Richard Gibbs. The 18/8 figure, with a 120 BPM tempo, is divided into 2 groups of 4 notes: 1st group played on the downbeats, 2nd group played on the upbeats. Each group is separated by 2 consecutive eight-notes rests on the 8th and 9th ones, resulting in a syncopated line but still keeping a feeling of even 4 notes played at an even interval: the 2nd group of