Composer of the Robertsbridge Fragment (b. c. 1290)
(Earliest written two-hand keyboard / organ music)
Organ Estampie No. 1 (1320)
Organ Estampie (1320) (Positive Organ)
The earliest-known extant keyboard music for two hands is the Robertsbridge Fragment, which is dated as early as c. 1320: three estampies and three intabulations of vocal music.
***
A positive organ (pronounced "positeev"; also positiv organ, positif organ, portable organ, chair organ, or simply positive, positiv, positif, or chair) (from the Latin verb ponere, "to place") is a portable one-manual pipe organ that may be moved without first being disassembled. It was common in sacred and secular music between the tenth and the seventeenth centuries, when it was used in the performance of basso continuo parts in ensemble works.
In the Middle Ages and the Renaissance, it was placed on a table or floor to be played, but many modern positive organs feature wheels. Before electricity, positives required a person to operate the bellows in order to supply wind to the instrument, but modern positives include electric blowers for this purpose.
Positive organs typically exhibit few stops due to their small size and portable nature; a specification of 8′, 4′, and 2′ flutes is common. Some positives may also have a 2-2/3′ stop, and some have an 8′ reed stop (such as a regal). More complex examples feature a divided keyboard, which allows each stop to be activated separately in the treble and bass portions of the keyboard. This makes it possible to play a melody and an accompaniment simultaneously on different registrations.
The positive organ differs from the portative organ in that it is larger and is not played while strapped at a right angle to the performer's body. It also has a larger keyboard (typically 49 notes or more), while a portative may have as few as 12 or 13 notes. The positive is also not to be confused with the regal, a small keyboard instrument that contains short-length reed pipes.
Positive organs were used at many kinds of civil and religious functions. They were used in the homes and chapels of the rich, at banquets and court events, in choirs and music schools, and in the small orchestras of Jacopo Peri and Claudio Monteverdi at the dawn of the musical drama or opera.
A well-known instance of an early positive or portable organ of the 4th century occurs on the obelisk erected to the memory of Theodosius I on his death in A.D. 395. Among the illuminated manuscripts of the British Museum there are many miniatures representing interesting varieties of the portable organ of the Middle Ages, including Add. MS. 29902 (fol. 6), Add. MS. 27695b (fol. 13), and Cotton MS. Tiberius A VII. fol. 104d., all of the 14th century, and Add. MS. 28962 and Add. MS. 17280, both of the 15th century.
In England they became known as chair organs, later to be corrupted into the "Choir" division found on modern organs.
[8291 Philippe de Vitry / 8290 Robertsbridge Fragment / 8283 Gervaise du Bus]
