Complex sentence: In 2008, she left Columbia Records and released a 15 song album called "These Four Walls" on her new label, Nonesuch Records which featured contributions by Patti Griffin and Teddy Thompson.
Split into simpler sentences: In 2008, she left Columbia Records and released a 15 song album called "These Four Walls" on the Nonesuch recording label. The album featured contributions by Patti Griffin and Teddy Thompson.