This dissertation considers how music has been heard with American law during an age of mass incarceration. Drawing upon records in legal archives for thousands of cases from the late 1980s to the present, it describes how legal hearings of music have contributed towards the reproduction of racial injustice. The dissertation takes two distinct modes of hearing as objects for analysis: (1) the hearing of music as evidence; and (2) the hearing of music as an offense. The dissertation describes how, since the late 1980s, the American criminal justice system has routinely and selectively heard rap music as evidence within its investigations and prosecutions. It shows how rap has served variously as a clue or lead during investigations, an aggravator of charges filed and sentences pursued during plea bargaining, a support for arguments against bail, a form of proof for elements of a crime or elements of a sentence enhancement allegation, a support for an affirmative defense, a witness impeacher, a form of proof for an aggravating factor in sentencing, and a support for arguments against parole. The dissertation questions whether quick-fix, colorblind policy proposals are likely to halt this selective hearing of rap, suggesting the need for frank discussions to take place about the political contours of problematization. The dissertation then describes how, over the same time period, through both the criminal justice system and the procedures of administrative law, music has been heard routinely as a subfelony offense. It shows how offenses have been heard in music to facilitate narcotics investigations, raise revenue for cash-strapped municipalities, patrol the borders of the nation, and drive residents from neighborhoods. It demonstrates how the academic study of music can become attentive to harms and injustices made possible through hearing that are not reducible to the restriction of musical freedom, including but not limited to harassment, profiling, the imposition of crushing debts, vehicle impoundment, eviction, and deportation, by engaging in fine-grained study of the social life of music’s regulative rules.