Founded in 1991, Gregorian is a German musical project conceived by producer, songwriter, and musician Frank Peterson (born in Hamburg, Germany on December 29, 1963). Connecting with producer Michael Cretu, Frank Peterson was invited to join pop singer Sandra’s band. Working several years with Sandra, who was Cretu’s wife, Frank Peterson became involved with the couple’s musical project Enigma. While he was heavily involved with the group’s debut 1990 debut album, MCMXC a.D., he left the Cretus and Enigma behind and started a similar group that he called Gregorian. In 1991, they released the album Sadisfaction, which featured the single “So Sad”. Musically, the group was similar to Enigma but did not achieve the enormous worldwide success of Michael Cretu’s musical project. Frank Peterson put the Gregorian project aside for most of the 1990s but revived it in 1998 with a different musical goal: to perform Gregorian chant-inspired versions of well-known pop and rock songs. In 1999, Gregorian released the first volume of their Masters of Chant series which included tracks originally performed by Dire Straits, R.E.M., Simone & Garfunkel, Metallica, and Percy Sledge. Gregorian released a total of eleven volumes in their Masters of Chant series between 1999 and 2016 alongside compilations and other related releases including Epic Chants (2012), Winter Chants (2014), Holy Chants (2017), and 20/2020 (2019).  Throughout their career, many vocalists have appeared on Gregorian’s albums including Sarah Brightman.