Lambert breaks down while singing song co-written with Shelton

Country star Miranda Lambert broke down in tears while singing a song she co-wrote with her ex-husband, Blake Shelton.
The 32-year-old songstress was performing in Chicago and got emotional when she started singing her 2012 single "Over You," reported Us magazine.
The songstress had to rely on her fans to help finish the emotional tune at Hollywood Casino Amphitheatre in Tinley Park, Illinois.
Later in her set, she broke down once again during "The House That Built Me."
"She was amazing. But emotionally unstable. Crying the whole show," a concert-goer said.
Lambert and Shelton, 40, wrote "Over You" as a tribute to his late older brother, who died when Shelton was a teenager. The song earned the former couple the 2012 Country Music Award for Song of the Year.