When people hear "oratorio" (a sacred story told with voice and musical instruments), they don't usually think of homelessness, addiction and mental illness - but this isn't your average oratorio. Over the past year, songstress Onalea Gilbertson has gathered vivid tales from the Calgary Drop-In Centre and teamed with composer Marcel Bergmann to create a sweeping composition that gives voice to the streets of Calgary.

Performed for one night only, this must-see event features Elizabeth Stepkowski-Tarhan, Doug McKeag, the Drop-In Centre Singers, the Land's End Chamber Ensemble and members of the choir Revv52. The evening also includes an exhibition of artwork by homeless citizens, information booths from social agencies and an audience talkback. Part of the proceeds will be donated to Calgary homeless shelters.