A Stroh violin, Stro(h)viol, violinophone, or horn-violin is a violin that amplifies its sound through a metal resonator and metal horns rather than a wooden sound box as on a standard violin. The instrument is named after its German designer, Johannes Matthias Augustus Stroh, who patented it in 1899.

In the 20^th century many types of horn-violins have been devised, especially in the Balkans.

Description and Background

Stroh violins are much louder than a standard wooden violin, and the directional projection of sound made the Stroh violin particularly useful in the early days of phonographic recording. As regular violins recorded poorly with the old acoustic-mechanical recording method, Stroh violins were common (though by no means universal) in recording studios. After record companies switched to the new electric microphone recording technology in the second half of the 1920s, Stroh violins became less common. While the Stroh produces significantly more volume, it does this at the expense of tone, offering a sound that is harsher and more grating than a standard violin. On early records the Stroh violin can be recognized by its characteristically thin whining tone.

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 theaters and music-halls. There was also a Stroh viola.

Current Usage

A few musicians, including Tom Waits, Carla Kihlstedt, Thomas Newman, Bat For Lashes, and Bob Cohen for the Klezmer and múm, and Fabrice Martinez with Fishtank Ensemble continue to use the Stroh violin for its distinctive sound.

The Stroh violin is also an instrument used in folk music of the Bihor region of Romania. Famous musicians of this music style are fiddlers like Gheorghe Rada, singers like Florica Bradu, Florica Ungur, Florica Duma, Leontin Ciucur, Cornel Borza, Vasile Iova, Maria Haiduc, Viorica Flintasu, and renowned folk ensembles like "Crisana" or "Rapsozii Zarandului".
In Buenos Aires (Argentina) back in the 1920s, Julio De Caro (renowned Tango orchestra director and violinist) used it on his live performances, and was called "violin corneta" (cornet violin) by the locals.

Rumanian horn-violin

An interesting variant on the Stroh violin is the Rumanian horn-violin that was built through the 20th century. It has the same length as the Stroh violin, but its horn is narrower and yields a more directional sound.
The structure of the instrument is based on the element of an old-fashioned gramophone and could for that reason easily be built by amateurs or small workshops. Therefore, there exist many variants in Eastern Europe.

The vibrations of the strings and bridge are transmitted by a thin rod to the membrane of the gramophone-element. The membrane transforms these vibrations into sound waves, which are amplified by the horn or beaker.
Also, this instrument is more difficult to play than a normal violin because the reaction of the bow on the strings is less flexible and the instrument's weight is less evenly distributed, which leads to an imbalance on the shoulder.
The instrument is still in use in Rumanian folk-music for playing horas and doinas and it mixes well with the characteristic sound of the pan-flute. Its individual tone is a welcome alternative for the sound of a Rumanian folk-music orchestra. However, it is generally used sparsely as the grating tone may become irritating after a while. Instruments like the Stroh violin and other types of horn-violin remain a curiosity; they are quite rare in the orchestra.