The Stroh-Violin or Stroviol is a violin that is mechanically amplified by a metal resonator and horn attached to its body. John Matthias Augustus Stroh, an electrical engineer in London, invented the instrument in 1899.
This is an another early attempt to make acoustic stringed instruments louder and is part of the move from acoustic to electric music instruments. The history of the Stroviols company is therefore fascinating, and even plays a role in the development of the National resonator instruments!
Finding any example of a Stroh-Violin or Horn-Violin though is a difficult thing to do. Whether these violins are satisfactory musical instruments seems subservient as they were once used a lot. They were definitely common place in the recording studio for two decades, at least. During this time they were the preferred instrument of choice by the most important recording companies. Normal violins had actually been discovered to be too weedy and feeble to make a good enough impression.
Very soon after the acoustic recording industry was born in the early 1900's and the technology and instruments became commercially available; the so-called “electric” device made its entrance. Electric devices did not just bring about the demise of acoustic recording and playback devices; they effectively brought an end to the use or need for a violin with a trumpet-horn attachment. The end regardless of whether Stroh, Parsons and others might only just be beginning to perfect their designs and mechanisms. The electric microphone effectively started a battle for supremacy between the traditional classical acoustic violin which could now be heard by means of subtly placed microphones and the electric violin which had to start completely from scratch, no guide, and no tradition. Which goes here for the violin was also true for the guitar. There was now the opportunity for something entirely new. Therefore it took also some time to give a final shape to the electric guitar.
In addition to the violin the Stroh technique was applied to viola, cello, mandoline and guitar. But Stroh was not alone exploring this technique. Sir Charles Algernon Parsons and others developed and patented at the same period similar devices but have gone unexplored, almost unnoticed.
Stroh's design was patented on May 4th 1899 - UK patent GB9418 titled "Improvements in Violins and other Stringed Instruments" which was accepted on March 24th 1900. The patent described the use of a flat metal (other materials are also mentioned) diaphragm in the voice-box (reproducer) of a violin to mechanically amplify the sound. On February 16th 1901 he applied for an additional UK patent (GB3393) titled "Improvements in the Diaphragms of Phonographs, Musical Instruments, and Anologous Sound-producing, Recording and Transmitting Contrivances" which was accepted on December 14th 1901. This effectively extended the first concept to now use a conical resonator with corrugations at its edge, allowing a more 'rigid' diaphragm. Interestingly, his failure to patent his inventions in the USA allowed John Dopyera and Geo Beauchamp to subsequently obtain US patents for the tricone and single cone designs used in National resonator instruments.
The Stroh violin was an expensive instrument: in 1911 it was offered by the London dealers Barnes & Mullins for nine guineas (£9.45, then equal to $37.80) or twelve guineas (£12.60 / $50.40) at a time when a reasonable factory violin could be had for two guineas. It was listed as being especially suitable for use in small theatres and music-halls.
The sound of the instrument is quite loud, and projects very well. It is of course a much more tinny or metallic tone (compared to a wood bodied instrument), yet still quite full and beautiful. This effectively extended the first concept to now use a conical resonator with corrugations at its edge, allowing a more 'rigid' diaphragm.
The instrument was and still today is used by musicians:
In 1920s Buenos Aires, Julio de Caro, a renowned Tango orchestra director and violinist, used the Stroh violin in his live performances, and was called violín-corneta (cornet violin) by the locals.
A number of musicians, including Tom Waits, Carla Kihlstedt, Thomas Newman, Bat for Lashes, A Hawk and a Hacksaw and Eric Gorfain continue to use the Stroh violin for its distinctive sound. Shakira featured a Stroh violin on her 2010/11 The Sun Comes Out World Tour, with multi-instrumentalist Una Palliser playing it on some songs. Palliser also played Stroh violin on Tom Hickox album and live with Bitter Ruin. Pinky Weitzman plays the Stroh violin for various New York experimental ensembles, including her own project (Not Waving but Drowning), as well as Flare, LD & the New Criticism, and as part of the onstage ensemble for Stephin Merritt's My Life as a Fairy Tale. A Stroh violin is regularly played by Andy Stein of Vince Giordano's Nighthawks, a New York-based band specialising in the music of the 1920s and 1930s. They Might Be Giants used a Stroh violin in their song, I Can Hear You, recorded on a wax cylinder at the Edison Laboratory. Lindsey Stirling features a Stroh violin in her latest video "Roundtable Rival".