Board Thread:Utaite Talk/@comment-41.249.164.77-20140510093131/@comment-4189484-20140724201832

i've found a page that suggests several solutions (skip to the 3rd paragraph):

http://vocalogy.wordpress.com/2014/07/19/the-best-alternative-to-nicosound-nicomimi/

if, for some songs, you only want to download the audio, keep an eye out for the "Music download" button that *may* show up when you open the menu on a video.