{"id":5447,"date":"2011-02-18T14:14:31","date_gmt":"2011-02-18T06:14:31","guid":{"rendered":"http:\/\/www.intmath.com\/blog\/?p=5447"},"modified":"2014-11-19T08:54:39","modified_gmt":"2014-11-19T00:54:39","slug":"friday-math-movie-pentatonic-scale","status":"publish","type":"post","link":"https:\/\/www.intmath.com\/blog\/videos\/friday-math-movie-pentatonic-scale-5447","title":{"rendered":"Friday math movie: pentatonic scale"},"content":{"rendered":"<p>This video has some nice math going on behind the music.<\/p>\n<p><i>Penta<\/i> is Latin for \"5\". (For example, a pentagon is a 5-sided figure.)<\/p>\n<p>In music, the Western \"major\" scale consists of 7 notes (called heptatonic). For example the C major scale has no sharps and no flats and consists of the notes C, D, E, F, G, A, B. An <b>octave<\/b> is the interval between 8 of these notes, C and the next highest C. (<i>Octo<\/i> is Latin for \"8\").<\/p>\n<p class=\"imgCenter\"><img loading=\"lazy\" src=\"\/blog\/wp-content\/images\/2011\/02\/c-major.png\" alt=\"C major scale\" width=\"376\" height=\"81\" \/><br \/>\nC major scale<\/p>\n<p>On the other hand, the <b>pentatonic<\/b> scale has 5 notes, one possible scale being C, D, E, G, A. Pentatonic scales are heard in music across all cultures (for example, jazz, folk music, Indonesian gamelan, and Scottish bagpipes).<\/p>\n<p class=\"imgCenter\"><img loading=\"lazy\" src=\"\/blog\/wp-content\/images\/2011\/02\/pentatonic.png\" alt=\"pentatonic scale\" width=\"293\" height=\"75\" \/><br \/>\nPentatonic scale<\/p>\n<p>One possible reason for the popularity of pentatonic scales is that if any 2 notes from the pentatonic scale are played together, there is no strong clash since their frequencies differ by a reasonable amount (e.g. C and D are 2 semitones apart), whereas in the 7-note Western scale, you get a discordant sound if you play E-F together or B-C together (they are only 1 semitone apart).<\/p>\n<p class=\"imgCenter\"><img loading=\"lazy\" src=\"\/blog\/wp-content\/images\/2011\/02\/discordant.png\" alt=\"discordant notes\" width=\"153\" height=\"78\" \/><br \/>\nDiscordant notes<\/p>\n<p>In such cases, you hear \"beats\", where the sound waves add together in such a way that it gives a shimmering effect and can be unpleasant.<\/p>\n<p>So let's get on with today's video. Bobby McFerrin, composer of \"Don't Worry, Be Happy\", gets his World Science Festival audience involved in the pentatonic scale.<\/p>\n<p><iframe width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/ne6tB2KiZuk?feature=oembed\" frameborder=\"0\" allowfullscreen><\/iframe><\/p>\n<p>For more on math in music, see:<\/p>\n<p><a href=\"https:\/\/www.intmath.com\/trigonometric-graphs\/music.php\">What are the frequencies of music notes?<\/a><\/p>\n<p><a href=\"https:\/\/www.intmath.com\/blog\/mathematics\/the-maths-of-music-427\">The math of music<\/a><\/p>\n<p><a href=\"https:\/\/www.intmath.com\/blog\/mathematics\/a-logarithmic-music-scale-740\">A logarithmic music scale<\/a><\/p>\n<p><a href=\"https:\/\/www.intmath.com\/fourier-series\/7-fast-fourier-transform-fft.php\">Fast Fourier Transform<\/a><\/p>\n<p class=\"alt\">See the <a href=\"https:\/\/www.intmath.com\/blog\/videos\/friday-math-movie-pentatonic-scale-5447#comments\" id=\"comms\">1 Comment<\/a> below.<\/p>\n","protected":false},"excerpt":{"rendered":"<p><a href=\"https:\/\/www.intmath.com\/blog\/videos\/friday-math-movie-pentatonic-scale-5447\"><img loading=\"lazy\" src=\"\/blog\/wp-content\/images\/2011\/02\/discordant_th.png\" alt=\"dissonant sounds\" width=\"128\" height=\"100\" class=\"imgRt\" \/><\/a>The pentatonic scale is popular across all cultures. Some math is involved here!<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_mo_disable_npp":""},"categories":[105],"tags":[125],"_links":{"self":[{"href":"https:\/\/www.intmath.com\/blog\/wp-json\/wp\/v2\/posts\/5447"}],"collection":[{"href":"https:\/\/www.intmath.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.intmath.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.intmath.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.intmath.com\/blog\/wp-json\/wp\/v2\/comments?post=5447"}],"version-history":[{"count":0,"href":"https:\/\/www.intmath.com\/blog\/wp-json\/wp\/v2\/posts\/5447\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.intmath.com\/blog\/wp-json\/wp\/v2\/media?parent=5447"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.intmath.com\/blog\/wp-json\/wp\/v2\/categories?post=5447"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.intmath.com\/blog\/wp-json\/wp\/v2\/tags?post=5447"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}