youtube -dl install mp3 code example

Example 1: how to use youtube dl for mp3

youtube-dl -x --audio-format mp3 https://www.youtube.com/watch?v=jwD4AEVBL6Q

Example 2: youtube-dl download audio

youtube-dl -F http://www.youtube.com/watch?v={video ID}  to get available audio
then
youtube-dl -f {number of available audio} http://www.youtube.com/watch?v={video ID}