Julius Keilwerth was a designer and builder of Keilwerth Saxophones in the early part of the 20th century. Though there are saxophones with serial numbers dating back to the 1920s, the actual history of the Keilwerth's company and whether it was founded in Germany or Czechoslovakia is vague.
The current Keilwerth Company is located in Nauheim, Germany just outside the city of Frankfurt.
Keilwerth Saxophones were sold under a number of brand names over the decades. Herbert Couf, who was the Vice-President of the W.T. Armstrong Company, imported Keilwerth horns that were engraved with the name "H. Couf." Three models of saxophones bearing the H. Couf name were brought into the United States. These included the Royalist, Superba I and Superba II which were similar to previous Keilwerth models. For a time, Keilwerth produced saxophone bodies that were finished by the Armstrong Company and carried the Armstrong name.
Other saxophones produced by Keilwerth were stenciled with Saxophone brands like Selmer Pennsylvania, Conn, Selmer Bundy, Boosey & Hawkes and Amati. Today, the German-made saxophones carry the Julius Keilwerth name and have been produced specifically for both the professional and the student jazz saxophonist.
In 1986, Keilwerth hired noted jazz saxophonist Peter Ponzol as a consultant to develop new instruments. Ponzol was largely responsible for bringing the SX90R Saxophone series to the professional market which was well received among jazz saxophonists. Professional musicians like Brandford Marsalis, Courtney Pine, Ernie Watts and James Moody, David Liebman, Ron Holloway and Mike Smith readily endorsed the SX90R series and used the instruments to further their professional careers. Professional models are available in standard brass and a black nickel-plated nickel and silver finish that is known as the "Shadow" series.
The Boosey & Hawkes Company bought Keilwerth in 1989 and then merged it with Schreiber in 1996. The Music Group acquired both companies in 2003, and by 2006, the Schrieber & Keilwerth Company had been split off to become an independent organization. In 2010, the assets of Keilwerth & Schreiber were acquired by the French firm of Buffet Crampton which maintains the Keilwerth name and production.
In additional to professional models, the Keilwerth name appears on a number of student and intermediate saxophones. The ST90 is designed for the student saxophonist while the EX90 serves the intermediate market. The SX90 and SX90R are professional models featuring soldered-on tone hole rings which produce a more consistent sound than the usual drawn tone holes. A number of the student models are produced by Keilwerth in Germany. Parts produced by Keilwerth are also shipped to the Czech Republic and assembled into finished units at the Amati production facility. The ST90 Series III and Series IV student horns are made in Taiwan.