These pages comprise a dictionary of terms relating to the pipe organ. Please keep definitions to a few sentences, and do not include pictures or sound clips. When more space is needed for a term, a new page can be created for it. Aeoline [noun] - a string stop usually at 8' pitch. In American usage, usually the softest stop on the instrument. Ancillary Division [noun] see Floating Division. Armature Valve Austin Organ Company - a long-time prominent American organ builder, founded in Hartford, Connecticut, in 1899, famous for many mechanical innovations.