[3] In 1941 he encountered for the first time the choir of the Regensburger Domspatzen, which he would later direct, when they performed in Salzburg on the occasion of the 150th anniversary of Mozart's death.

[8] In 2010 Ratzinger indicated he would be prepared to testify to aid investigations into claims of abuse at the Regensburger Domspatzen choir in Germany.

[8] A man who lived in the choir-linked boarding school until 1967 contended that "a sophisticated system of sadistic punishments in connection with sexual lust" had been installed there.

[11] A Vatican spokesperson stated that the allegations on sexual abuse, particularly the Regensburg case, are a campaign aimed against the pope and the Roman Catholic Church comparable to Nazi propaganda.

[12] A lawyer commissioned by the choir to look into the accusations concluded that over 200 young singers were abused to various degrees, with at least 40 of the cases involving sexual violence, and that he must assume that Ratzinger had known.

[13] A report in 2017 faulted Ratzinger "in particular for 'looking away' or for failing to intervene" and also stated that, "with a high degree of plausibility", between the years 1945 and 1992, 547 boys were victims of physical or sexual abuse, or both.

[16] In 2005, during a visit to his brother in Rome, symptoms of heart failure and arrhythmia led to a brief admission at the Agostino Gemelli University Polyclinic.

[17] On 29 June 2011, Ratzinger celebrated 60 years as a priest and gave an interview on the topic, during which he noted that during the ordination ceremony, "My brother was the second to youngest, though there were some who were older."