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In linguistics, speech synthesis, and music, the pitch contour of a sound is a function or curve that tracks the perceived pitch of the sound over time. Pitch contour may include multiple sounds utilizing many pitches, and can relate the frequency function at one point in time to the frequency function at a later point.
It is fundamental to the linguistic concept of tone, where the pitch or change in pitch of a speech unit over time affects the semantic meaning of a sound. It also indicates intonation in pitch accent languages.
One of the primary challenges in speech synthesis technology, particularly for non-tonal languages, is to create a natural-sounding pitch contour for the utterance as a whole. Unnatural pitch contours result in synthesis that sounds "lifeless" or "emotionless" to human listeners, a feature that has become a stereotype of speech synthesis in popular culture.
In music, the pitch contour focuses on the relative change in pitch over time of a primary sequence of played notes. The same contour can be transposed without losing its essential relative qualities, such as sudden changes in pitch or a pitch that rises or falls over time. Often used in the analysis of post-tonal music, Michael Friedmann's methodology [1] for analyzing pitch contour assigns numeric values to notate where each pitch falls in relation to the others within a musical line; the lowest pitch is assigned "0" and the highest pitch is assigned the value of n-1, in which n= the number of pitches within the segmentation. Therefore, a contour that follows the sequence of low, middle, high, would be labeled as contour classes 0, 1, and 2.
Pure tones have a clear pitch, but complex sounds such as speech and music typically have intense peaks at many different frequencies. Nevertheless, by establishing a fixed reference point in the frequency function of a complex sound, and then observing the movement of this reference point as the function translates, one can generate a meaningful pitch contour consistent with human experience.
For example, the vowel [e] has two primary formants, one peaking between 280 and 530 Hz and one between 1760 and 3500 Hz. When a person speaks a sentence involving multiple [e] sounds, the peaks will shift within these ranges, and the movement of the peaks between two instances establishes the difference in their values on the pitch contour.
Additive synthesis is a sound synthesis technique that creates timbre by adding sine waves together.
Rhythm generally means a "movement marked by the regulated succession of strong and weak elements, or of opposite or different conditions". This general meaning of regular recurrence or pattern in time can apply to a wide variety of cyclical natural phenomena having a periodicity or frequency of anything from microseconds to several seconds ; to several minutes or hours, or, at the most extreme, even over many years.
In music, harmony is the concept of combining different sounds together in order to create new, distinct musical ideas. Theories of harmony seek to describe or explain the effects created by distinct pitches or tones coinciding with one another; harmonic objects such as chords, textures and tonalities are identified, defined, and categorized in the development of these theories. Harmony is broadly understood to involve both a "vertical" dimension (frequency-space) and a "horizontal" dimension (time-space), and often overlaps with related musical concepts such as melody, timbre, and form.
Absolute pitch (AP), often called perfect pitch, is the ability to identify or re-create a given musical note without the benefit of a reference tone. AP may be demonstrated using linguistic labelling, associating mental imagery with the note, or sensorimotor responses. For example, an AP possessor can accurately reproduce a heard tone on a musical instrument without "hunting" for the correct pitch.
Music theory is the study of the practices and possibilities of music. The Oxford Companion to Music describes three interrelated uses of the term "music theory": The first is the "rudiments", that are needed to understand music notation ; the second is learning scholars' views on music from antiquity to the present; the third is a sub-topic of musicology that "seeks to define processes and general principles in music". The musicological approach to theory differs from music analysis "in that it takes as its starting-point not the individual work or performance but the fundamental materials from which it is built."
In music, timbre, also known as tone color or tone quality, is the perceived sound quality of a musical note, sound or tone. Timbre distinguishes different types of sound production, such as choir voices and musical instruments. It also enables listeners to distinguish different instruments in the same category.
Pitch is a perceptual property that allows sounds to be ordered on a frequency-related scale, or more commonly, pitch is the quality that makes it possible to judge sounds as "higher" and "lower" in the sense associated with musical melodies. Pitch is a major auditory attribute of musical tones, along with duration, loudness, and timbre.
The cent is a logarithmic unit of measure used for musical intervals. Twelve-tone equal temperament divides the octave into 12 semitones of 100 cents each. Typically, cents are used to express small intervals, to check intonation, or to compare the sizes of comparable intervals in different tuning systems. For humans, a single cent is too small to be perceived between successive notes.
Musical acoustics or music acoustics is a multidisciplinary field that combines knowledge from physics, psychophysics, organology, physiology, music theory, ethnomusicology, signal processing and instrument building, among other disciplines. As a branch of acoustics, it is concerned with researching and describing the physics of music – how sounds are employed to make music. Examples of areas of study are the function of musical instruments, the human voice, computer analysis of melody, and in the clinical use of music in music therapy.
A pitch detection algorithm (PDA) is an algorithm designed to estimate the pitch or fundamental frequency of a quasiperiodic or oscillating signal, usually a digital recording of speech or a musical note or tone. This can be done in the time domain, the frequency domain, or both.
In music, transcription is the practice of notating a piece or a sound which was previously unnotated and/or unpopular as a written music, for example, a jazz improvisation or a video game soundtrack. When a musician is tasked with creating sheet music from a recording and they write down the notes that make up the piece in music notation, it is said that they created a musical transcription of that recording. Transcription may also mean rewriting a piece of music, either solo or ensemble, for another instrument or other instruments than which it was originally intended. The Beethoven Symphonies transcribed for solo piano by Franz Liszt are an example. Transcription in this sense is sometimes called arrangement, although strictly speaking transcriptions are faithful adaptations, whereas arrangements change significant aspects of the original piece.
Evolutionary musicology is a subfield of biomusicology that grounds the cognitive mechanisms of music appreciation and music creation in evolutionary theory. It covers vocal communication in other animals, theories of the evolution of human music, and holocultural universals in musical ability and processing.
Svara is a word that connotes simultaneously a breath, a vowel, the sound of a musical note corresponding to its name, and the successive steps of the octave or saptaka. More comprehensively, it is the ancient Indian concept about the complete dimension of musical pitch. Most of the time a svara is identified as both musical note and tone, but a tone is a precise substitute for sur, related to tunefulness. Traditionally, Indians have just seven svaras/notes with short names, e.g. saa, re/ri, ga, ma, pa, dha, ni which Indian musicians collectively designate as saptak or saptaka. It is one of the reasons why svara is considered a symbolic expression for the number seven.
Music theory analyzes the pitch, timing, and structure of music. It uses mathematics to study elements of music such as tempo, chord progression, form, and meter. The attempt to structure and communicate new ways of composing and hearing music has led to musical applications of set theory, abstract algebra and number theory.
Jaroslav Volek was a Czech musicologist, semiotician who developed a theory of modal music. His theory included ideas of poly-modality and alteration of notes that he called "flex," which result in what he called the system of flexible diatonics. He applied this theory to the work of Béla Bartók and Leoš Janáček. He wrote General Theory of Art based on semiotic concepts in 1968.
In physics, sound is a vibration that propagates as an acoustic wave through a transmission medium such as a gas, liquid or solid. In human physiology and psychology, sound is the reception of such waves and their perception by the brain. Only acoustic waves that have frequencies lying between about 20 Hz and 20 kHz, the audio frequency range, elicit an auditory percept in humans. In air at atmospheric pressure, these represent sound waves with wavelengths of 17 meters (56 ft) to 1.7 centimeters (0.67 in). Sound waves above 20 kHz are known as ultrasound and are not audible to humans. Sound waves below 20 Hz are known as infrasound. Different animal species have varying hearing ranges.
Psychoacoustics is the branch of psychophysics involving the scientific study of sound perception and audiology—how the human auditory system perceives various sounds. More specifically, it is the branch of science studying the psychological responses associated with sound. Psychoacoustics is an interdisciplinary field including psychology, acoustics, electronic engineering, physics, biology, physiology, and computer science.
Harmonic pitch class profiles (HPCP) is a group of features that a computer program extracts from an audio signal, based on a pitch class profile—a descriptor proposed in the context of a chord recognition system. HPCP are an enhanced pitch distribution feature that are sequences of feature vectors that, to a certain extent, describe tonality, measuring the relative intensity of each of the 12 pitch classes of the equal-tempered scale within an analysis frame. Often, the twelve pitch spelling attributes are also referred to as chroma and the HPCP features are closely related to what is called chroma features or chromagrams.
The generative theory of tonal music (GTTM) is a system of music analysis developed by music theorist Fred Lerdahl and linguist Ray Jackendoff. First presented in their 1983 book of the same title, it constitutes a "formal description of the musical intuitions of a listener who is experienced in a musical idiom" with the aim of illuminating the unique human capacity for musical understanding.
Traditional sub-Saharan African harmony is a music theory of harmony in sub-Saharan African music based on the principles of homophonic parallelism, homophonic polyphony, counter-melody and ostinato-variation. Polyphony is common in African music and heterophony is a common technique as well. Although these principles of traditional African music are of Pan-African validity, the degree to which they are used in one area over another varies. Specific techniques that used to generate harmony in Africa are the "span process", "pedal notes", "rhythmic harmony", "harmony by imitation", and "scalar clusters".