{"id":14612,"date":"2017-12-19T22:20:46","date_gmt":"2017-12-20T03:20:46","guid":{"rendered":"http:\/\/scruss.com\/blog\/?p=14612"},"modified":"2017-12-20T13:42:23","modified_gmt":"2017-12-20T18:42:23","slug":"synthesizing-simple-chords-with-sox","status":"publish","type":"post","link":"https:\/\/scruss.com\/blog\/2017\/12\/19\/synthesizing-simple-chords-with-sox\/","title":{"rendered":"Synthesizing simple chords with sox"},"content":{"rendered":"

SoX<\/a> can do almost anything with audio files \u00e2\u20ac\u201d including synthesize audio from scratch. Unfortunately, SoX’s syntax is more than a bit hard to follow, and the manual page isn’t the most clear. But there is one example in the manual that gives a glimpse of what SoX can do:<\/p>\n

play -n synth pl G2 pl B2 pl D3 pl G3 pl D4 pl G4 \\ \r\n     delay 0 .05 .1 .15 .2 .25 remix - fade 0 4 .1 norm -1\r\n<\/pre>\n
While it plays a nice chord, it’s not obvious how to make audio files from this process. I have a project coming up that needs a few simple guitar chords, and with much trial and error I got SoX to spit out audio files. Here’s what I keyed into the shell:<\/p>\n
\r\ncat guitar.txt | while read chord foo first third fifth\r\ndo\r\n  echo "$chord" :\r\n  sox -n \\ \r\n    -r 16000 -b 16 "chord-${chord}.wav" \\\r\n    synth pl "$first" pl "$third" pl "$fifth" \\\r\n    delay 0 .05 .1 \\ \r\n    remix - \\ \r\n    fade 0 1 .095 \\ \r\n    norm -1\r\ndone\r\n<\/pre>\n
with these lines in the file \u00e2\u20ac\u0153guitar.txt\u00e2\u20ac\u009d<\/p>\n
G   :  G2  B2  D3\r\nC   :  C3  E3  G4\r\nD   :  D3  F#4 A3\r\nF   :  F3  A3  C4\r\nA   :  A3  C#4 E4\r\nE   :  E2  G#3 B3\r\nEm  :  E2  G3  B3\r\n<\/pre>\n
How the SoX command line breaks down:<\/p>\n