Consider the question. "Man in the Mirror" is a song recorded by Michael Jackson, written by Glen Ballard and Siedah Garrett and produced by Jackson and Quincy Jones. It peaked at number 1 in the United States when released in January 1988 as the fourth single from his seventh solo album, Bad (1987). It was nominated for Record of the Year at the Grammy Awards.

Answer this question based on the passage: who wrote michael jackson's man in the mirror?
What is the step-by-step reasoning process to arrive at the answer: Glen Ballard?
To answer the above question, the relevant sentence is: "Man in the Mirror" is a song recorded by Michael Jackson, written by Glen Ballard and Siedah Garrett and produced by Jackson and Quincy Jones.