A double stop, in music terminology, is the act of playing two notes simultaneously on a melodic percussion instrument (like a marimba

Marimba

The marimba is a musical instrument in the percussion family. It consists of a set of wooden keys or bars with resonators. The bars are struck with mallets to produce musical tones. The keys are arranged as those of a piano, with the accidentals raised vertically and overlapping the natural keys ...

) or stringed instrument

String instrument

A string instrument is a musical instrument that produces sound by means of vibrating strings. In the Hornbostel-Sachs scheme of musical instrument classification, used in organology, they are called chordophones...

 (for example, a violin

Violin

The violin is a string instrument, usually with four strings tuned in perfect fifths. It is the smallest, highest-pitched member of the violin family of string instruments, which includes the viola and cello....

 or a guitar

Guitar

The guitar is a plucked string instrument, usually played with fingers or a pick. The guitar consists of a body with a rigid neck to which the strings, generally six in number, are attached. Guitars are traditionally constructed of various woods and strung with animal gut or, more recently, with...

). In performing a double stop, two separate strings are depressed ("stopped") by the fingers, and bowed or plucked simultaneously (without a string change

String change

On string instruments, a string change is a change from playing on one string to another. This may also involve a simultaneous change in fingering and/or position , all of which must be done skillfully to avoid noticeable string noise. String may be indicated through roman numerals or simply the...

).

A triple stop is the same technique applied to three strings; a quadruple stop applies to four strings. Double, triple, and quadruple stopping are collectively known as multiple stopping.
The invention of the double-stop is generally credited to violinist Carlo Farina

Carlo Farina

Carlo Farina was an Italian composer, conductor and violinist of the Baroque era.-Life:Farina was born at Mantova. He presumably received his first lessons from his father, who was sonatore di viola at the court of the Gonzaga in Mantova. Later he got further education probably by Salomone Rossi...

, whose Capriccio Stravagante (1627) was published in Dresden while he was Court-Violinist at Saxony.

Technique

On instruments with a curved bridge

Bridge (instrument)

A bridge is a device for supporting the strings on a stringed instrument and transmitting the vibration of those strings to some other structural component of the instrument in order to transfer the sound to the surrounding air.- Explanation :...

, it is difficult to bow more than two strings simultaneously. The style of bow

Bow (music)

In music, a bow is moved across some part of a musical instrument, causing vibration which the instrument emits as sound. The vast majority of bows are used with string instruments, although some bows are used with musical saws and other bowed idiophones....

 used until around the end of the 18th century, particularly in Germany

Germany

Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

, had the wood curved outwards (away from the hair), which made it somewhat easier to play three notes at the same time. However, most treatises written around the time make it clear that composer

Composer

A composer is a person who creates music, either by musical notation or oral tradition, for interpretation and performance, or through direct manipulation of sonic material through electronic media...

s did not expect three notes to be played at once, even though the notes may be written in a way as to suggest this. Playing four notes at once is almost impossible, even with older bows. The normal way of playing three or four note chords is to sound the lower notes briefly and allow them to ring while the bow plays the upper notes (a broken chord). This gives the illusion of a true triple or quadruple stop. In forte

Dynamics (music)

In music, dynamics normally refers to the volume of a sound or note, but can also refer to every aspect of the execution of a given piece, either stylistic or functional . The term is also applied to the written or printed musical notation used to indicate dynamics...

, however, even with a modern violin and bow it is quite possible to play three notes at once, especially when played a little more towards the fingerboard

Fingerboard

The fingerboard is a part of most stringed instruments. It is a thin, long strip of material, usually wood, that is laminated to the front of the neck of an instrument and above which the strings run...

. Obviously, with this technique, a little more pressure than usual is needed on the bow

Bow (music)

In music, a bow is moved across some part of a musical instrument, causing vibration which the instrument emits as sound. The vast majority of bows are used with string instruments, although some bows are used with musical saws and other bowed idiophones....

, so this cannot be practised in softer passages. Of course, great skill is needed for the player to keep a beautiful sound. This technique is mainly used in music with great force, such as the cadenza-like solo at the beginning of the last movement of Tchaikovsky's violin concerto

Violin Concerto (Tchaikovsky)

The Violin Concerto in D major, Op. 35, written by Pyotr Ilyich Tchaikovsky in 1878, is one of the best known of all violin concertos. It is also considered to be among the most technically difficult works for violin.-Instrumentation:...

.

Bach bow

A 20th century invention by Emil Telmányi

Emil Telmányi

Emil Telmányi, b. 22 June 1892 in Arad, then in the Kingdom of Hungary, d. 13 June 1988 in Holte, Denmark was a Hungarian violinist who invented the Bach bow, designed to play and sustain three or four notes on a violin for Bach's sonatas and partitas for solo violin...

 called the "Bach bow" uses a system of levers to temporarily slacken the bow hair and allow sustained three- or four-note chords; this design has no historical precedent, and is no more authentic than an ordinary modern bow for playing baroque music

Baroque music

Baroque music describes a style of Western Classical music approximately extending from 1600 to 1760. This era follows the Renaissance and was followed in turn by the Classical era...

.

Bridge curvature

In addition to the style of bow, the curvature of the bridge is an important factor in the ease of multiple stopping. On most classical instruments, the bridge is curved enough to make it difficult to play three strings at once, but on some violins the bridge is shaved down until almost flat, making it far easier to triple stop, as well as to alternate double stopping on different pairs of strings (D-A to A-E for example). The compromise is that more skill is needed to avoid playing a double stop when none is called for.

Percussion stops

Multiple stops are also used in tuned percussion, such as on the vibraphone

Vibraphone

The vibraphone, sometimes called the vibraharp or simply the vibes, is a musical instrument in the struck idiophone subfamily of the percussion family....

 or marimba

Marimba

The marimba is a musical instrument in the percussion family. It consists of a set of wooden keys or bars with resonators. The bars are struck with mallets to produce musical tones. The keys are arranged as those of a piano, with the accidentals raised vertically and overlapping the natural keys ...

, and more rarely, timpani

Timpani

Timpani, or kettledrums, are musical instruments in the percussion family. A type of drum, they consist of a skin called a head stretched over a large bowl traditionally made of copper. They are played by striking the head with a specialized drum stick called a timpani stick or timpani mallet...

. A percussion double stop simply consists of striking both bars or timpani with two separate mallets

Drum stick

A percussion mallet is an object used to beat drums and other percussion instruments. Some specialized mallets are called beaters, drumsticks.Note: See Rute .-Drum sticks:...

.