On seizing power on 11 September 1973, General Augusto Pinochet established over a thousand detention centers, from the Atacama Desert to the Magellan Strait. Tens of thousands of prisoners were held in these centers, without recourse to fair trials and lacking elementary judicial guarantees. Most inmates were subjected to serious abuse through physical and psychological torture; many were killed, their bodies "disappeared." Despite the regime of terror, precarious living conditions and censorship, prisoners developed diverse musical activities on their own initiative, including composition, peiformance and teaching. Pinochet's system also used music to indoctrinate detainees and as a form of and soundtrack to torture. Evidence of the above is fragmented and little known, and has been largely overlooked by critics. This article documents and contextualizes the testimony of a former agent of Pinochet's secret police recently interviewed by the author, discussing the musical landscape of various detention and torture centers in Santiago and the provinces, including Chacabuco, Londres 38, Villa Grimaldi, Tejas Verdes, Iran 3037 (aka La Discotheque) and Jose Domingo Canas 1305. To the present day, this is the most detailed account specifically dealing with forced musical activities in captivity during the Pinochet regime, but also the only one coming from a Chilean ex-agent.