Johann Reiter was among the leading makers of the Mittenwald school of violin making. Born in 1879, he was one of the few craftsmen in his hometown who did not work for larger factories. He inherited his style from his father, Johann Baptist Reiter (1834–1899), another great name in the Mittenwald tradition, who in turn had been a pupil and disciple of the legendary Jean Vauchel (1782–1856).

Johann Reiter was not only a brilliant violin maker, but also a refined researcher, a multi-instrumentalist, and an artist inclined toward experimentation. He has been credited with the creation of original instruments such as the octave violin and the viola pomposa. This latter attribution, however, has been disputed.

In 1936, the renowned Bavarian master became the centre of a controversy after claiming the invention of an instrument that had long been envisioned and that Johann Sebastian Bach himself had attempted to develop, but which had in fact been built several years earlier by a skilled violin maker from Casalbuttano, Luigi Digiuni. The instrument was named the Violetto and essentially revived ideas formulated centuries earlier by Bach concerning the viola pomposa and the violoncello piccolo.

The dispute between the German luthier and the Cremonese craftsman, on the eve of the Stradivarian celebrations of 1937, found no place in the local press. Neither Regime Fascista nor the magazine Cremona reported on the matter, both being subject to the strict control of Roberto Farinacci, who at that time was weaving an increasingly close network of relations with Hitler's Germany and had little interest in antagonising a powerful ally over a question of priority in violin making.

News of the controversy appeared instead in a number of Italian newspapers published between 7 and 21 September 1936, including La Gazzetta del Popolo and Stampa Sera of Turin, Il Popolo d'Italia of Milan, Il Popolo di Roma, and several others. Thanks to these reports, justice was eventually done to the Cremonese violin maker who, during one of the darkest periods in the history of violin making, sought to preserve the reputation of the great masters.

This was an episode and a figure that might easily have been forgotten even at the time, had it not been for the dispute that reached the national press and, after Digiuni's death the following year, helped secure him the recognition he deserved during the celebrations dedicated to the greatest of violin makers.

Stampa Sera explained the matter in an article published on 7 September 1936:

"In recent days many newspapers have reported that the Bavarian violin maker Johann Reiter, a pupil of Mathias Klotz, has recently patented in Germany a new bowed instrument intermediate between the viola and the violoncello, an instrument that Sebastian Bach had already attempted to obtain through the 'viola pomposa'. It produces a tenor voice that has until now been lacking in string quartets and allows the parts of cellos and basses to be performed in chamber orchestras.

Italy, however, may claim priority in this invention thanks to a Cremonese violin maker, Luigi Digiuni, who conceived and built such an instrument in 1922, named it the 'Violetto', and presented it in 1923 at the Interprovincial Exhibition of Artistic Industries held that year in Cremona.

On that occasion a concert of string instruments was also held, and the Violetto was played by distinguished professional musicians who praised it highly. The matter nevertheless ended there. Yielding to the encouragement of acquaintances, Digiuni later patented the instrument and obtained official Industrial Patent No. 230,533 from the then Ministry of the National Economy on 19 September 1924, while the application, accompanied by the required documentation, had been deposited with the Prefecture of Cremona on 10 May 1924 at two o'clock in the afternoon.

The patent described the instrument as a 'new type of stringed musical instrument, Digiuni-system bass violin'. Digiuni built three examples of the instrument, but the economic crisis and the declining demand for musical instruments discouraged further production. One example was sold, while two remained in his possession.

The instrument, played on the shoulder like a violin, had a body length of 40 centimetres. It was intermediate between the viola and the violoncello and possessed a particularly pleasing tone. Its lowest string corresponded to the third string of the cello; compared with the cello, it lacked only the low C string.

Digiuni was inspired to study and build the instrument in 1922 after reading in a treatise on violin making that, in previous centuries, there had existed a leg instrument smaller than the cello but with a sweeter and more powerful voice than the viola. He decided to create a similar instrument to be played on the arm, and his first intention was to perform on it himself, being an accomplished violinist."