So much of the Persian music was absorbed by the Arab that it would be difficult to separate them in our story. The Arabs took the very loosely-put-together music of Persia and made it over into better form. Even before the Mohammedan conquests (700–800 A.D.), Arab music was well planned, and as they spread later to North Africa, Egypt, Morocco, Greece, Italy, and Spain, they left some traces of their own music and took something of the music of the natives. Furthermore, they adopted many of the instruments that they found and they became the ancestors of some of our own.
The ancient Arabs did not write down their music, but handed it on from musician to musician, gaining and losing very little from the many hands through which it passed. They have none of what we call harmony or accompaniment, as in their orchestras all the instruments except the drums play the same tune; the drums mark the time and often play very complicated rhythms. This makes their music sound confused to us, but by hearing it often you learn in what an orderly way it is done, and you will see why many people like it.
The caliphs (rulers) had court musicians and probably more music was played and more scientific treatises on music were written by these people than by any other mediæval or ancient race.
The Arab Scales
There has been much argument about Arab music as to whether the scale was divided into seventeen steps or eight, as is our scale. Some people think they hear it as seventeen tones divided into one-third steps, but Baron d’Erlanger, a great authority on ancient Arab music, says that there are two distinct musical systems still in use. One comes from their ancient home in Asia, and the other from the Pharaohs of Egypt. And the fact that these two systems have been mixed in using them leads to the question of what the real scale is. Baron d’Erlanger finds, as the result of his experiments, that if we could lower, ever so slightly, the third and seventh tones of our scale, we would have the old Pharaoh scale in its simplest form. The other scales can be played on stringed instruments on which there are no fixed tones as there are on a keyboard instrument like a piano, and can therefore play the intervals that do not exist on the piano.
Laura Williams, American Singer of Arab Songs, in Native Costume, Accompanying Herself on El oud (the Lute).
It is impossible to say how many scales or modes the Arabs use, because each change of the tiniest part of a step creates a new mode, and there are many combinations possible. Some say that there are thirty-four modes; another says that there are twenty-four, one for each hour of the day. There are also modes for the four elements—fire, water, earth, and air; for the twelve signs of the zodiac, and for the seven planets.
Each mode has a name, called after all sorts of things like cities or tribes or ornaments, in fact, anything familiar to the people.
The weird effects made by the Gloss or musical ornaments like the trill, grace notes and slidings give the music a dreamy fascinating character, the charm of which is increased by its frequent changes from double to triple time, or from triple to double.