Dictionary of Music - Birding America

differential tone 107D-flat One of the musical tones (see PITCHNAMES), one half tone below D and one half toneabove C. On the piano, D-flat is identical with C-sharp (see ENHARMONIC for an explanation). Themajor scale beginning on D-flat is known as D-flatmajor. A composition based on this scale is said tobe in the key of D-flat major, the KEY SIGNATURE forthis key being five flats. For the location of D-flat onthe piano, see KEYBOARD.di For Italian musical terms beginning with di,such as di nuovo, see under the next word (NUOVO).diapason (English dī′′ ə pā′ zən; French dyA pAZÔN′). 1 A group of organ pipes that provide thebasic tone of the instrument (see ORGAN; PRINCIPAL,def. 1). 2 The entire range of a voice or instrument.3 French for PITCH. 4 French for TUNING FORK.diapason normal (dyA pA ZÔN′′ nôr mAl′). TheFrench term for CONCERT PITCH, which in 1859 wasestablished as the A above middle C at a frequencyof 435 cycles per second.diatonic (dī′′ə ton′ik). 1 Pertaining to or containingthe notes that make up an octave containing fivewhole tones and two half tones. Both the major andminor scales are diatonic, as are the CHURCH MODES.For example, one such arrangement is F, G, A, B♭,C,D, and E, constituting the scale of F major;the remaining notes, which do not belong to thisscale, are termed chromatic. Naturally, the termsfig. 79 p/u from p. 110“diatonic” and “chromatic” apply only when aspecific key (scale) is in question. In music whereno particular key is used (see ATONALITY) the termshave no meaning. 2 Proceeding by scale degrees.3 Using DIATONIC HARMONY.diatonic chord A chord made up only of diatonicnotes, for example, F–A–C in the key of F major;the chord F–A–C♯ , on the other hand, is called achromatic chord, since it contains a chromatic note(C-sharp).diatonic harmony Harmony that consists chieflyof diatonic chords (it is rarely possible to exclude allchromatic notes).didgeridoo Also, didjeridu (did′jer i doo — ′′) Australianaborigine. An end-blown straight naturaltrumpet, without a separate mouthpiece, that is usedby Australian aborigines. The average instrument is1 to 1.5 meters (39 to 59 inches) long, with a bore of3.5 to 7.5 centimeters (1.3 to 2.9 inches) but exceptionallylarge ones, 2.5 meters long, are used in specialceremonies. It sounds a bass drone with wavesof high overtones. Among the aborigines thedidgeridoo may be played only by men. In additionto ceremonial functions, it is used to accompanysinging and dancing, supply rhythm and tone coloras well as being used as a drone. Western composersuse it occasionally, as Annea Lockwood does inThousand Year Dreaming (1993) for ten instrumentsand Philip Glass in Voices (2001) for didgeridoo andorgan.Dies irae (dē′ās ēr′e) Latin: “day of wrath.” Asection of the Roman Catholic Requiem Mass (theMass for the dead) whose text and music date fromthe thirteenth century. Although early composersof Requiem Masses used the original monophonic(with a single voice-part) music for this section asa SEQUENCE, later composers, among them Mozartand Verdi, set the words to more dramatic music oftheir own. The original music has also been usedto suggest the idea of death in some secular (nonreligious)compositions, as by Saint-Saëns in hisDanse macabre (“Dance of Death”) and byBerlioz in his Symphonie fantastique (“FantasticSymphony”).diferencia (dē fe ren′thē ä) Spanish: “variation.”A musical form consisting of THEME AND VARIA-TIONS. Many fine diferencias for lute and keyboardinstruments were written by Luis de Narvaez, Antoniode Cabezón, and other sixteenth-century Spanishcomposers. Narvaez was one of the first to use theform of theme and variations, which he developed toan extent extraordinary for his time.differential toneSee under TARTINI, GIUSEPPE.