Sketch for an altarpiece

This is an image that evokes a sacred scene. On the left there's an altar to which the bystanders, the officiant and his acolyte are turned; around them ther's a crows of togates. A similar group is in a niche above on the right. The sketch, that was done quickly, had to refer to an altarpiece destined to a church in Parma, not yet identified.