<Artist>–<Title>-<Karaoke||Lyrics>

To batch convert videos to MP3 in a folder, use the for command-line as below:

FOR /F "tokens=*" %G IN ('dir /b *.mp4') DO "c:\Program Files (x86)ffmpeg\bin\ffmpeg.exe" -i "%G" -f mp3 -ab 128000 "%~nG.mp3"