Hope-Jones also developed an imitative version of the diaphone called the diaphonic horn , which had a more reed-like quality than the diaphone and was voiced on lower wind pressures. Wurlitzer built a version of the diaphonic horn for their theater organs at 32′ and 16′ pitches with huge wooden resonators as extensions of its Diaphonic diapason, and at 16′ with metal resonators as an extension of its smaller-scale Open diapason. The Austin Organ Company also developed a metal diaphone at 16′ pitch known as a Magnaton. Due to its penetrating tone, a diaphone-type horn has also been used in foghorns and fire signals.
During the Romantic period, the organ became more symphonic, capable of creating a gradual crescendo. New technologies and the work of organ builders such as Eberhard Friedrich Walcker , Aristide Cavaillé-Coll , and Henry Willis made it possible to build larger organs with more stops, more variation in sound and timbre, and more divisions.  Enclosed divisions became common, and registration aids were developed to make it easier for the organist to manage the great number of stops. The desire for louder, grander organs required that the stops be voiced on a higher wind pressure than before. As a result, a greater force was required to overcome the wind pressure and depress the keys. To solve this problem, Cavaillé-Coll configured the English " Barker lever " to assist in operating the key action. 
About Hammond Organ "Green Onions" by Booker T. and the .'s would not be the same without that catchy Hammond organ riff. It could have a bit of flair on a keyboard or a jazzy feel on an acoustic piano, but its true soul comes from the electric organ. The Hammond organ was originally marketed to churches as a cheaper alternative to the giant pipe organs traditionally used to play church music, but the instrument quickly took off with jazz musicians. In present day, the electric organ is commonplace in a wide variety of musical genres, such as soul, rock, and rhythm and blues. You can even hear it in a few hip hop tracks. You can play full-sized Hammond organs that have the look and feel of the original instruments or opt for compact keyboard-style instruments. Hammond organ parts and accessories, such as pedals, switches, and controls add distinct sounds to your music, letting you produce those unforgettable hooks, riffs, and solos. Whether you play the organ at church or you slam those keys in a jazz band, you can find a large inventory of organs and parts on eBay, as well as accessories such as original Hammond organ benches.