Kristen Stewart continues her preparations for the role of rocker Joan Jett on Tuesday.

Sporting a new shorter, darker hairstyle and dressed in her usual jeans/t-shirt/hoodie combo, the 19-year-old actress was snapped leaving a studio in North Hollywood carrying a guitar case.

Kristen leaving a studio in North Hollywood on Tuesday (Splash News)

Kristen and New Moon co-star Dakota Fanning are shooting The Runaways – about the 70s teen band of the same name – in the break before filming on the Twilight saga resumes with Eclipse later this year.

Kristen in rehearsals for her role as the teenage Joan Jett (left), and Joan performing in 2008 (right, Splash News)

The pair - who are expected to record their own vocals for the movie - rehearsed at a vocal studio together on Monday.

The Runaways is slated for release in 2010.

Kristen's style rocks!