I'm a beginner pianist, and I asked my teacher about the possibility of playing some Persian music on the piano. He told me it's typically not possible, but didn't really elaborate on why. So why is it that the piano shouldn't be able to play that music? Could I play it on the guitar, or violin, then?
A modern piano is tuned to 12-TET, 12-tone equal temperament. 12-TET is what's called a tuning system, almost all current Western music uses it. It basically means 12 notes per octave and the notes are spread equally, it's the same distance (measured in fractions of an octave) between all of them.
Persian music uses a different system. I'm no expert, but Essentials of Persian music says that there are three competing models to describe Persian music:
- 24-tone scale, like 12-TET but with an extra quartertone between each semitone.
- 22-tone scale, not tied to 12-TET
- "Flexible intervals" with regional variations, not tied to any particular scale or tuning system. A researcher recorded many performers and measured the intervals used in practice, and found that the whole tone and semi-tone were fairly stable intervals, but several other intervals between a semi- and a whole tone were very flexible. (Perhaps analogous to blue notes used in blues, where there is no standard for how "blue" or flat the note should be, it's up to the performer.)
Whether there are 24, 22, or some other number of tones per octave, it's more than the 12 on a piano, and many of the them are tuned differently. Demo of differences between quarter tones in Persian/Arabic/Turkish music.
Piano can't play that. Instruments that can fall in two groups: Some have continously variable pitch (e.g. violin or trombone), while others have a standard 12-tone fingering but can pitch bend a semitone or more so it can cover all the intermediate pitches as well (e.g. saxophone, synthesizer, probably fretted guitar).
The issues of tuning systems have been addressed, but there is an additional problem.
Pianos can be — and have been — retuned to accommodate, for example, quarter-tone music.
The truly "impossible" part of Arabic and Persian music — not to mention Indian, Chinese, Japanese, and many, many other cultures — is the ornamentation, which plays an essential, central role. The ornamentation requires the bending of pitches, which a fixed-pitch instrument like the piano simply cannot accommodate.
For a significant discussion of ornamentation in Arabian music, see Lois Ibsen al Faruqī, "Ornamentation in Arabian Improvisational Music: A Study of interrelatedness in the Arts", The World of Music 20/1 (1978): 17–32.
Possible but effort prohibitivePersian music makes use of quartertones/microtones that fall in between the typical note progressions of western classical music (at least for the piano). Let's suppose we did have a kind of framework in mind (maqiano or otherwise) there is also the logistics of the process to consider. Tuning a piano even under normal circumstances is surprisingly complicated and potentially dangerous to you or the instrument if done improperly; many often turn to professionals for this. So we can only imagine how short the list would be for piano tuning services that understand oriental music. Absent professional help, we'd be attempting to tune a very sophisticated instrument by ourselves. At the very minimum we'd need beyond perfect pitch ears and an oriental tuner.
If we somehow got that far and tuned it full-Persian, then we may face other issues. The player interface of the piano is clearly designed for half-steps. Once you have quarter-tones in the mix, you'd lose the whole intuition of the white and black keys. This is especially problematic when the quartersteps don't line up with existing western scales and is further complicated if you did decide to play in a different Persian key -- probably feeling even weirder than normal and affecting muscle memory. So the process, would not be very scalable or intuitive, even if it is 'theoretically' possible.
Further issues arise once we view Persian music in the complete context: Dastgahs. These 12 scales/patterns form the framework for improvisation that provides the scaffolding of Persian music. In addition to your Persian piano, you'd need some really elaborate notation to handle not only the tones but irregular rhythms and other Oriental music quarks. I can recommend this book for more on Dastgahs:
why is it that the piano shouldn't be able to play that music?
Without knowing much about Middle Eastern music, the obvious answer would seem to be "tuning". Within its range, which must be amongst the largest if not the largest of any instrument, it can only play the notes it is tuned to play. It cannot play the notes between them.
Could I play it on the guitar, or violin, then?
Not so easy on the guitar, because it is fretted and so suffers to a lesser degree to the same problem as the piano.
Should be easy on the violin, insofar as playing with correct intonation on the violin can be described as "easy".
Pianos are tuned basically to '12tet'. Which means they can play anything in any key, and it will sound at least o.k.
There are many other tuning systems, and I believe Middle Eastern tuning systems use other tuning systems which will not align exactly with 12tet. So, on a 'properly' tuned piano, the discrepancies in pitch between certain notes are not available, making any other music using any different tuning systems basically unavailable.
Trombones, violins, and other instruments will be able to find those elusive pitches, because they can play notes 'in the cracks' as we say.
Piano = you would need to re-program the keyboard to use a microtone scale. probably the easiest way to do this would be to use a midi keyboard and a program that allows microtone assignment. do a search for the "apotome" project
Guitar = they make microtone guitars that have more frets than a standard guitar. these are more difficult to play as the frets are much closer together
Violin = you should be able to do this on a standard violin, but your fingers and ears will need to be "re-programmed"
Unless the piano is a player piano, a piano can't play any type of music ;-)
Also, and I mean this seriously, I'm not sure what you mean by 'middle eastern music'. The Middle East is a large region comprised of many countries spanning 3 continents. There are and have been many musicians there and they do practice and have practiced many different styles.
But I think the answer you are looking for is already given. Modern pianos are tuned using equal temperament and many musical traditions from the Middle East use other tuning methods that feature pitches not found on a modern piano. This is a big, big topic and touches not only on music theory and ethno-musicology but also physics, acoustics, and cognitive science.
However, I am not very enthusiastic about some of the previous answers, and believe that they provide some very misleading and problematic information.
The link provided by @j-g-faustus (https://theoryofmusic.wordpress.com/2008/06/09/essentials-of-persian-music-part-2/) describes the intervals used in Persian music in terms of 'cents' which means percentage of an equal tempered whole-tone. Since equal temperament is not the tuning system with which that musical tradition derived its modes, it is not in any way shape or form an appropriate way to describe it. To do so is a bit like analyzing ancient Japanese prints using a theory of art developed to describe Renaissance Italian painting.
Nor is the notion of "Flexible intervals" a good description of what is actually going on. Many scales are built on harmonic relationships built on whole number ratios (3:2, for example, is the frequency ratio of a perfect 5th---this interval by definition does not exist in 12tet). Using such ratios to construct a theory of melodic intervals results in pitches that cannot be found on a piano.
Statements like this: 'Equal temperament makes the complex harmonies of modern Western music possible, and this impressed musicians from the Middle East who came into contact with western art music. These musicians viewed the absence of harmony in their own music as a sign of inferiority to western music. The desired musical advancement was thought possible only through the adoption of western harmonic practice. That, in turn, required equidistant tones.' should be eschewed at all costs. Ali-Naqi Vaziri may have thought that, but it rather assumes quite a lot about many people's relationship to their own musical traditions.
I also find this statement from the link in @j-g-faustus very difficult to believe: '..no Middle Eastern musical instrument is capable of producing intervals of such precision [as found in the theories of the medieval theorists]; and vocal music is even more unreliable in producing accurate intervals.' Granted, I don't know and cannot know what medieval theorists the author refers to or what their theories entail, but I do know that musicians, particularly vocalists, are capable of being very accurate about pitch---particularly when placing the pitches of notes in a scale based on whole-number frequency ratios against a drone.
@Aaron's answer is also somewhat problematic. While it is true that most keyboard instruments cannot bend pitch (certainly not a modern piano), they can still approximate glissandi ornaments in their own way. I would point out that in Classical Indian Music, singers are often accompanied by a harmonium player who plays the raga in unison with the vocalist---ornaments included. By the same token it is technically impossible to perform a slur on a piano. That did not stop Beethoven from writing literally hours of piano music with slurs in it. Nor has it stopped literally millions of pianists from having performed those slurs.