Youtube Mp3 Today - Convert youtube videos to mp3 in 1 click every time
Yout - YouTube to Mp3 Converter
MediaHuman YouTube to MP3 Converter - Extracts MP3 audio from YouTube, Vimeo, Dailymotion, Mixcloud, Bandcamp, SoundCloud and many others. Available for macOS, Windows and Ubuntu/Linux. FREE!
Softorino YouTube Converter - Download YouTube video & audio. Watch and listen offline
yt2mp3.org - Free online YouTube to MP3 Converter
You-Get - Command-line utility to download media contents from the web