GitHub - matthew-asuncion/Fast-YouTube-to-MP3-Converter-API: Very Fast YouTube to MP3 & MP4 Converter API JSON, Python, JavaScript, iFrame, PHP, Android & iOS Video Downloader API
MP3 Converter - Free MP3 Converter, Convert to MP3, Convert Video to MP3, Convert Audio to MP3, Convert YouTube to MP3
How to convert YouTube videos to MP3 files | Mashable