​DOUBLE STOPPING is sounding on the violin or other instrument of that tribe two notes simultaneously. Such notes are termed 'double stops.' An 'open note' is produced by merely striking the string with the bow without touching it with the fingers of the left hand—so that the string vibrates in its whole length. A 'stopped note' is a note produced by putting a finger of the left hand on the string, so that the vibration of the string is 'stopped' at a certain point.

Strictly speaking, the term 'double-stopping' ought only to be applied to the simultaneous sounding of two 'stopped' notes; it is, however, indiscriminately used for any double sounds, whether produced with or without the aid of the open strings. The playing of double stops is one of the most difficult parts of the technique of the violin.