In the image below, Mevlevi ancient neys
(from Konia, Jelaluddin Rumi Mevlana Museum)
  One of the oldest forms of flute is the ney, the endblown flute played in slightly varying forms from Morocco to Pakistan. The word is Farsi for reed, and indeed the nay is made in its traditional form from the Arundo Donax plant. The differing internodal pattern of the Arundo Donax is used in a specific fashion to make ney. Some modern makers have experimented with some success with replacing the reed by a metal pipe or a PVC pipe; however good-sounding, though, the finest sound comes from a well made natural cane ney.The name "ney" is used by Turks and Persians; many Arabs pronounce the word as Nai; thus we can distinguish between the Turkish, Arab and Persian forms of the instruments.

The oldest form, shown on Egyptian tomb paintings as early as 3000-2500 years BC, is of a nine-segment section of reed, the first node at the wider mouthpiece end opened with a part of the node left making a small hole, and the other nodes fully opened, with an outside bevel around the embouchure. Six fingerhholes plus a thumbhole make for fully chromatic and quarter-tone scalar possibilities. 

Around 1200AD the Turks began using turned wood, bone, horn and now even plastic mouthpieces, really lip-rests, but otherwise kept the same fingering and lip technique. This embouchure is called bi-labial blowing, as both upper and lower lip are used to partially close the end of the tube; this is not the same as blowing a shakuhachi, quena, flute, or even a bottle, but a unique method of its own. Both Arab nai and Turkish ney are played with the pads of the fingers, not the tips, rather like a bagpiper's grip. They also come in different lengths, each one being tuned to a specific pitch, so that like a pennywhistle, if you know a melody in one key, switching to the appropriate ney or nai will then let you play the same melody but transposed to another key.

The Arabic ney/nai are pitched by the name of the note made with the 1st fingerhole open.

Turkish neys are marked by the name of the note with all holes closed.

Thus, with Turkish neys, we have, for instance, Mansur Ney, which is in G and which has G as its bottom note.

In Arabic fashion, we would call it an A ney. The Arabic standard (Rast=C) nai is one at D. This means that all the holes closed render a C; the 1st hole open, D, then respectively Eb, E1/2b, F, F#, G. This is for the lowest octave and for the 1st register, differing by an octave; the 2nd register overblows a fifth higher, the same sequence of holes rendering the notes A, Bb, B 1/2b, C, C#, D; the 3rd register plays an octave above the 1st register, C, D, etc. Other notes are made by partially opening a tonehole, changing the blowing angle or a combination of the above. Also note that the G note in the 1st register is the same pitch as the all-holes-closed note in the 2nd, as is the C in the 2nd reg. and the closed C of the 3rd (Arabic ney); these alternate fingerings are used for musical purposes and to check internal tuning (in Turkish "akord").

Arabic style of playing is generally more rhythmic, and reflective of the shepherd association, as the nai is commonly a pastoral instrument. The classical nai is usually longer, the folk models shorter.

The Turkish style is more smooth and flowing, betraying the Dervish association. In Turkey, the Mevlevi (Whirling Dervishes) long ago adopted the ney as their main instrument in the sema, the spiritual service that includes the trance dancing spinning.

The pastoral association is weaker in Turkey, the ney being a learned, urban Classical instrument; various types of kaval, smaller flutes of end and fipple blown types fill in the folk world.

Iran adopted the Turkoman inter-dental blowing method and altered the fingering pattern in the late 1700's, corresponding to a change in their musical style, and thus the modern Persian ney is of a different # of nodes, has a different embouchure, and has only 5 fingerholes and a lower-placed thumbhole than the Arab-Turkish types. The interdental blowing method is also very difficult to learn but gives a much louder, reedier tone color ; in the lower range where the Arab/Turk flute is at its softest, the Persian ney produces a full, rich tone.