The mercy seat, also called the penitent form, is a plain bench running across the front of the hall below the platform, and it is the physical centre of Salvationist worship. The meeting builds toward the invitation to come and kneel at it — to be converted, to seek holiness, to make any decision at all — and someone kneels beside the person and prays with them. Meetings are otherwise informal by the standards of any liturgical church: songs from the Song Book of The Salvation Army accompanied by brass, testimonies given standing from the floor, and preaching aimed at decision. The brass band is not decoration either; bands were formed in the 1870s and 1880s because brass carries over a street crowd, and the Army has commissioned a substantial body of original music that is performed well outside it.