In general design, the musical needs from a box organ is a beautiful stopped eight foot that can accompany a single voice or instrument, a four foot that blends well with the eight and gives enough power if an obligato part is introduced. Then a two foot that was bright enough but not too strong for a choral group.  For concerto’s it is better to have a fourth stop to give the instrument a distinct colour different to the other instruments. 

In this instrument the fourth stop is a Principal 4, more useful in the liturgical setting that it resides in.  Some sixty instruments of this type have been made, one with five divided stops for a church in the Blackforest, many with four stops of widely varying character, including an all wood pipe instruments.  Some six English and one German cathedral have permanent instruments as well as other important churches such as Brompton Oratory and St George’s, Windsor.