Gregorian chants generally don't have too much in common with rock music. Sure, sometimes they set a brooding tone in an intro to a doom metal song, but rockers generally scream, growl, wail or sing. They don't chant. German music producer, Frank Peterson, who previously performed in the elevator rock band Enigma, likes defying convention.

His new group Gregorian, releases an album this week, 'The Dark Side of the Chant,' which features gothic seven tone chant versions of songs by AC/DC, Evanescence, Within Temptation, Madonna and others.

One of the highlights from the record, a cover of AC/DC's 'Hell's Bells' (an obvious favorite amongst Gregorian monks), is streaming now at

Gregorian 'The Dark Side of the Chant'  Track List:

1. 'O Fortuna' (Carl Orff – Carmina Burana)
2. 'Bring Me To Life' (Evanescence)
3. 'Stripped' (Depeche Mode)
4. 'Dark Side' (Gregorian)
5. 'All I Need' (Within Temptation)
6. 'Frozen' (Madonna)
7. 'Hell’s Bells' (AC/DC)
8. 'Black Wings' (Gregorian)
9. 'Born To Feel Alive' (Unheilig)
10. 'Lucifer' (Alan Parsons Project)
11. 'Morning Dew'  (Bonnie Dobson)
12. 'Dark Angel' (Gregorian)