The nail violin is a musical instrument which was invented by German violinist Johann Wilde in 1740.

[3] Wilde was inspired to create the instrument when he accidentally drew his bow across a metal peg, which produced a musical sound.

An improved instrument, now in the collection of the Hochschule in Berlin, has two half-moon sound-chests of different sizes, one on the top of the other, forming terraces.

[3] Senal had modified the instrument by adding sympathetic strings, and dubbed this enhanced version the "violino harmonico".

A Nineteenth Century modification, called the Stockspiel or Melkharmonica, incorporated wooden rods, which were played using rosined gloves.