YouTube-DL GUI 0.4 Ships With New User Interface, More [PPA] ~ Web Upd8: Ubuntu / Linux blog
GitHub - Tom-van-Grinsven/youtube-dl-mp3
Downloading YouTube videos as MP3 files with youtube-dl, ffmpeg, and batch scripts -
GitHub - udidoron/youtube-dl-multi-mp3-downloader: Small wrapping script in Python (2.7), which allows downloading multiple YouTube files' audio into mp3 files. Uses youtube-dl, ffmpeg and ffprobe.