The curved bow for string instruments enables string players to control the tension of the bow hairs in order to play one, two, three and four strings simultaneously and to change easily among these possibilities. The high arch of the bow allows full, sustained chords to be played and there is a lever mechanism that affects the tension and release of the bow hairs.

The practice of polyphonic playing is documented by Alessandro Striggio

Alessandro Striggio

Alessandro Striggio was an Italian composer, instrumentalist and diplomat of the Renaissance. He composed numerous madrigals as well as dramatic music, and by combining the two, became the inventor of madrigal comedy...

 (1540–92), violinist Nicolaus Bruhns

Nicolaus Bruhns

Nicolaus Bruhns was a German organist, violinist, and composer. He was one of the most prominent organists and composers of his generation.-Life:...

 (1665–97), and German violinist Johann Paul von Westhoff

Johann Paul von Westhoff

Johann Paul von Westhoff was a German Baroque composer and violinist. One of the most important exponents of the Dresden violin school, he was among the highest ranked violinists of his day, and composed some of the earliest known music for solo violin...

 (1656–1705), who also developed a unique notation for that. There exist also some polyphonic pieces for violin and viola by Niccolò Paganini

Niccolò Paganini

Niccolò Paganini was an Italian violinist, violist, guitarist, and composer. He was one of the most celebrated violin virtuosi of his time, and left his mark as one of the pillars of modern violin technique...

 (1782–1840), documented by Dr. Philippe Borer.

Ever since the publication in 1905 of Albert Schweitzer

Albert Schweitzer

Albert Schweitzer OM was a German theologian, organist, philosopher, physician, and medical missionary. He was born in Kaysersberg in the province of Alsace-Lorraine, at that time part of the German Empire...

's book about J. S. Bach

Johann Sebastian Bach

Johann Sebastian Bach was a German composer, organist, harpsichordist, violist, and violinist whose sacred and secular works for choir, orchestra, and solo instruments drew together the strands of the Baroque period and brought it to its ultimate maturity...

, the question of the curved bow has been widely debated. For Schweitzer, however, use of the curved bow was essential in performing Bach’s string works. Asked to write something for the Bach year in 1950 (Bach-Gedenkschrift), forty-five years after his original study, Schweitzer still focused on his ideas about the curved bow.

Certain musicologists (D. Boyden, for example) have questioned the use of the curved bow, but their notions seem to be based more on theory than actual use of the bow itself. Two texts, on the other hand, clearly document use of the curved bow: Rudolf Gaehler’s book Der Rundbogen für Violine - ein Phantom? (The Curved Bow for Violin - a Phantom?), and Michael Bach’s article on the Suites for Cello of J.S.Bach.

In 1990, German cellist Michael Bach

Michael Bach (cellist, composer, visual artist)

Michael Bach is a German cellist, composer, and visual artist, also known as Michael Bach Bachtischa.-Biography:...

 had invented a curved bow for cello, violin, viola and bass. He named it "BACH.Bogen" (BACH.Bow).
During the years 1997 and 2001, Mstislav Rostropovich was intimately involved in the development and testing of the BACH.Bogen. He invited Michael Bach to present his curved bow on the occasion of the 7ème Concours de violoncelle Rostropovitch in Paris 2001.

John Cage

John Cage

John Milton Cage Jr. was an American composer, music theorist, writer, philosopher and artist. A pioneer of indeterminacy in music, electroacoustic music, and non-standard use of musical instruments, Cage was one of the leading figures of the post-war avant-garde...

, Dieter Schnebel

Dieter Schnebel

Dieter Schnebel is a composer. From 1976 until his retirement in 1995, Schnebel served as professor of experimental music at the Berlin Hochschule der Künste.-Career:...

, Walter Zimmermann

Walter Zimmermann

Walter Zimmermann is a German composer.Zimmermann studied composition in Germany with Werner Heider and Mauricio Kagel, the theory of musical intelligence at the Institute of Sonology in Utrecht , and computer music at Colgate University in New York.Zimmerman's works are infused by a personal...

 and Hans Zender

Hans Zender

Johannes Wolfgang Zender is a German conductor and composer.-Life:From 1956 to 1959 Zender studied piano, conducting, and composition at the Hochschule für Musik Frankfurt and at the Hochschule für Musik Freiburg.From 1959 to 1963 he was Kapellmeister of the Municipal Theatres in Freiburg im...

have written works for the curved bow which explore the new perspectives and potential of it.