Fans are worried about Brandy after she disappeared backstage mid-song during The Boy Is Mine Tour, and Monica emotionally ended the concert early before they could perform their hit duet together. Source: Vaughn Alvarez / Vaughn Alvarez Is our fave ok? What seemed like a brief technical issue at the Chicago stop of the highly anticipated tour raised concerns that something much more serious had happened. It remains unclear exactly what shut down Brandy and Monica's show on Saturday night.