چکیده:
این پژوهش شامل بررسی تطبیقی نغمههای رایج ساز رباب در رسالۀ موسیقی کبیر فارابی با گام زارلن است که در پاسخ به سوال اصلی تحقیق با عنوان: چگونگی ارتباط گام زارلن با نغمات رباب شکل گرفته است. بدین منظور، نخست نغمات موجود در ساز مذکور را آنالیز نموده، سپس آنها را ضمن شرح و تفسیر مختصر گام زارلن با استفاده ازضرب و تقسیم نسبتهای ریاضی موجود، با گام مطرح شده انطباق دادهایم که در نتیجۀ این مقایسه مشخص شد، نغمات مذکور در شرایطی با گام دیاتونیک زارلن مطابق است اما در گام کروماتیک ساختاری متفاوت دارند. در بررسی مجدد گام زارلن متوجه شدیم علاوه بر ایرادهای رایج که شامل وجود چهارم درست بزرگتر از 4:3 و پنجم درست کوچکتر از 3:2 است، ایرادی دیگر به ساختار گام زارلن وارد است. در حالی که محققان تاکنون بر این باورند که این گام دارای دونوع نیمپردۀ کروماتیک و یک نوع نیمپردۀ دیاتونیک است نتایج این مقاله مشخص میکند که گام مذکور دارای دونوع نیمپردۀ دیاتونیک و یک نوع نیمپردۀ کروماتیک است. با توجه به رویکرد توصیفی-تحلیلی این پژوهش برای برطرف ساختن آن ایراد نظریۀ اصلاحی مطرح میشود که پس از اعمال آن نغمات ساز رباب و گام زارلن انطباق کامل خواهند داشت.
The current research contains a comparative analysis of the intervals of the instrument of Robab, as recorded in Al-Farabi’s book of the title ‘Al-Mousighi Al-Kabir’, against the Zarlinian scale, pursuant to the research’s main question: the relation between Robab’s intervals and those of the Zarlinian scale. Firstly, the intervals frequency ratios of the Robab instrument have been analyzed, then together with a brief explanation of the Zarlinian scale, they have been compared against intervals of the Zarlinian scale by means of multiplying and dividing the corresponding mathematical proportionalities. In a reevaluation of the Zarlinian scale, notwithstanding its commonly-known problems which include a perfect fourth with a frequency ratio greater than that of 4:3 and the perfect fifth with a frequency ratio less than that of 3:2, we found another problem regarding the formation of the Zarlinian scale. While researchers currently believe that this scale consists of two kinds of a chromatic semitone, and one kind of a diatonic semitone, this article will prove that the said scale is comprised of two kinds of a diatonic, and only one kind of a chromatic semitone. Conclusion: Findings we achieved in this article could be divided into four divisions as given below: A] Interval frequency ratios of the Robab instrument, according to Farabi’s book titled Al-Mousighi Al-Kabir, fully conform to that of the diatonic major scale based on the Aristoxen-Zarlinian system of intonation. B] Lack of conformity of the intervals ratios of frequencies, within the said instrument with that of the chromatic Aristoxen-Zarlinian scale. C] Stating a problem pertaining to the Aristoxen-Zarlinian theory of intonation system based on the arrangement of chromatic intervals therein: In former theories, the Aristoxen-Zarlinian scale was believed to contain a kind of diatonic semitone with a proportion of 16:15, equal to 28.02 Savarts, and equal to 111.72 Cents. Also two kinds of a chromatic semitone with proportions of: A] in tone major equal to 135:128, equal to 23.12 Savarts, and equal to 92.17 Cents. And B] the chromatic semitone in tone minor, with a proportion of 25:24 equal to 17.72 Savarts, and equal to 70.66 Cents. Given a major scale from the upper chromatic semitone based on these proportions, the placement of major and minor intervals would become interchanged. D] Suggesting a reformative theory: According to findings in this article, the mentioned scale consists of two kinds of a diatonic semitone, and only one kind of a chromatic semitone as explained below: Diatonic semitone in major tone: proportion equal to 16:15 equal to 28.02 Savarts, equal to 111.72 Cents. diatonic semitone in minor tone: proportion equal to 256:243 equal to 22.63 Savarts, equal to 90.21 Cents. And the chromatic semitone: proportion equal to 135:128, equal to 23.12 Savarts, equal to92.17 Cents. Given the mentioned frequency ratios above, intervals of the said instrument will fully conform to ratios of the chromatic Aristoxen-Zarlinian scale. Also if a major scale would be formed based on these ratios on the upper chromatic semitone, minor and major semitones won’t get switched anymore.