Computer Music An Interactive Approach Aristotle University of Thessaloniki Department of Informatics 2015

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Introduction to Computer Music From Sound Waves and the Hearing Mechanism to Musical Instruments Dionysios Politis Dionysios Politis

6 Contents Part Α : Physical Properties of Sound Waves Part Α : Physical Properties of Sound Waves Part B : The Ear, the Listening Apparatus and Psychoacoustics Part B : The Ear, the Listening Apparatus and Psychoacoustics Part C : Musical Scales, Properties of Music and Musical Instruments Part C : Musical Scales, Properties of Music and Musical Instruments

7 From sound to music: We have seen thus far that the understanding of the music “language” is virtually a culture that gets into our perception as a highly cerebral activity. From sound to music: We have seen thus far that the understanding of the music “language” is virtually a culture that gets into our perception as a highly cerebral activity. Part C: Musical Scales, Properties of Music and Musical Instruments

8 If we cannot understand the brainwork that lies behind this activity, then we are unable to indulge how music perpetrates our existence as a language with considerable diachrony and synchrony … If we cannot understand the brainwork that lies behind this activity, then we are unable to indulge how music perpetrates our existence as a language with considerable diachrony and synchrony … There are more than 7000 spoken languages currently. However, music seems to be able to overcome the linguistic barriers! There are more than 7000 spoken languages currently. However, music seems to be able to overcome the linguistic barriers!

9 Therefore we cannot explain sufficiently why for instance in the modern era different sound families are perceived as masterpieces, despite the abysmal difference in sound metrics! Therefore we cannot explain sufficiently why for instance in the modern era different sound families are perceived as masterpieces, despite the abysmal difference in sound metrics!

10 … and therefore we cannot explain sufficiently why for instance in the modern era different sound families are perceived as masterpieces, despite the abysmal difference in sound metrics!

11 … and therefore we cannot explain sufficiently why for instance in the modern era different sound families are perceived as masterpieces, despite the abysmal difference in sound metrics!

12 Musical Scales, Properties of Music and Musical Instruments Pitch is the frequency we estimate that a certain sound corresponds to. Pitch is the frequency we estimate that a certain sound corresponds to. The human ear can discriminate on average some 1400 different pitches. The human ear can discriminate on average some 1400 different pitches. Even further, for the well tempered scale only 120 discrete tones seem to play the game within the audible range, from note A 0 = 27.5 Hz to C 8 = 4186 Hz. Even further, for the well tempered scale only 120 discrete tones seem to play the game within the audible range, from note A 0 = 27.5 Hz to C 8 = 4186 Hz. However, instruments like the trombone or the violin family can produce in between tonal frequencies. However, instruments like the trombone or the violin family can produce in between tonal frequencies.

13 Keys Notation and semiotics comprise the written paraphernalia of music. Notation and semiotics comprise the written paraphernalia of music. A key usually is responsible for the anchoring of notes … A key usually is responsible for the anchoring of notes … … and, surprisingly, for the Westerner, there are alternative music symbols, some times older than the common music notation! … and, surprisingly, for the Westerner, there are alternative music symbols, some times older than the common music notation!

14Alterations The symbol The symbol of sharpening a note raises the frequency of a note for a semitone while symbol (from bemolle) lowers the frequency of a note for a semitone… and the symbol of a natural sign restores notes to their normal frequency height. Byproducts for alterations are symbols and with a rather obvious meaning …

15Alterations Alas, the story is not over yet. In fact, it has just began to take off, since for the first time our inspiration has met alternative traditions on microtonal music on devising new scales with multiple alterations, with symbols like this or this and for instruments like this! Alas, the story is not over yet. In fact, it has just began to take off, since for the first time our inspiration has met alternative traditions on microtonal music on devising new scales with multiple alterations, with symbols like this or this and for instruments like this!

16 Note Duration The rendition of a note relies on its proper time length association. The rendition of a note relies on its proper time length association. The kind of note seen on the right, indicates for the Common Music Notation the relative length of time: The kind of note seen on the right, indicates for the Common Music Notation the relative length of time: Whole note Whole note Half note Half note Quarter Note Quarter Note Eighth note Eighth note Sixteenth note Sixteenth note Thirty-second note Thirty-second note Sixty-fourth note Sixty-fourth note

17 Rhythm The rendition of a note relies on its proper time length association. The rendition of a note relies on its proper time length association. The kind of note seen on the right, indicates for the Common Music Notation the relative length of time: The kind of note seen on the right, indicates for the Common Music Notation the relative length of time: The recurrence of these time accents in equal intervals of time yields the rhythm of a passage. The recurrence of these time accents in equal intervals of time yields the rhythm of a passage. Whole note Whole note Half note Half note Quarter Note Quarter Note Eighth note Eighth note Sixteenth note Sixteenth note Thirty-second note Thirty-second note Sixty-fourth note Sixty-fourth note

18 Rests Of course, under certain conditions, the performers are asked to silence themselves. This situation is indicated by the rests… Of course, under certain conditions, the performers are asked to silence themselves. This situation is indicated by the rests… Whole rest Whole rest Half rest Half rest Quarter rest Quarter rest Eighth rest Eighth rest Sixteenth rest Sixteenth rest Thirty-second rest Thirty-second rest Sixty-fourth rest Sixty-fourth rest

19 Intervals and Scales The interval between two notes is the frequency distance of their pitches. The interval between two notes is the frequency distance of their pitches. Since antiquity the arrangement of tones builds up scales. Since antiquity the arrangement of tones builds up scales. Important for building up scales is defining ratios that represent frequency intervals. Important for building up scales is defining ratios that represent frequency intervals. Octave is the ratio of 2:1 Octave is the ratio of 2:1 Perfect fourth is the ratio of 4:3 Perfect fourth is the ratio of 4:3 Perfect fifth is the ratio of 3:2 Perfect fifth is the ratio of 3:2 Tone is the ratio of 9:8 Tone is the ratio of 9:8

Ioannis Kaimakis, Scales in practice …

Ioannis Kaimakis, are instrument dependant