Isaac Brock

After having signed Lisa Molinaro to his Glacial Pace label in 2010, with her band Talkdemonic, the pair soon entered into a relationship. Molinaro joined Modest Mouse as a multi-instrumentalist and vocalist in 2011.

In October 2005, Brock started his own record label called Glacial Pace. The label used to be a subsidiary of Epic Records, but is now independent. Its first signee was Minnesota songwriter Mason Jennings, followed by Love As Laughter, Marcellus Hall, Mimicking Birds, Morning Teleportation, Talkdemonic, Survival Knife, Nocturnal Habits, and Mattress.

Brock is a former A&R person for the record label Sub Pop; his most notable accomplishment with them was signing Wolf Parade in 2004.

He has talked about the DUIs he has gotten and cutting himself onstage with a pocket knife. His songs have also addressed his substance abuse, as in "The Good Times Are Killing Me." Brock admits to past drug use, and now says that drugs are "just something I kind of have to fight... I just try and make sure that it's not around, or I'm not around it." In a 2003 interview with Salut Les Copains Magazine, Isaac explained how the decision to quit drugs was influenced by his experiences. "'...I was laying down in this aisle, at Powell's Books, reading an atlas when this meth-head tripped over me.'" Isaac said, "'He called me a faggot and mumbled as he wandered off. I saw a reflection of myself and didn't want to be seen like that.'"

Brock has two children, Aidan, born February 2, 2002, and according to High Times magazine published November 2018, he also has a daughter, born some time in 2018.

In 1992, when he was sixteen, Brock moved to Washington, D.C. for the summer where he met his girlfriend. Brock traveled back and forth from the East Coast to Issaquah, where he took a community-college course to get his high school diploma before moving back to D.C., to New York's East Village, and then the Seattle area. It was there that he, Eric Judy (bass) and Jeremiah Green (drums) first started practicing music together in the Shed.

Isaac Kristofer Brock (born July 9, 1975) is the lead singer, guitarist, banjoist, and songwriter for the American indie rock band Modest Mouse, as well as his side project band, Ugly Casanova. As a songwriter he is noted for wordplay and frequent use of metaphors, philosophical lyrics, themes of oppressive rural lifestyles, and certain phrases and sayings commonly used in the early to mid-20th century and in blue collar environments.