Itβs a simple extension of Emacs using helm to interact with xmm2.
You should run `helm-xmms2` to search in collection or playlist, you can then append or insert the song you found.
Some other command are available like helm-xmms2-play, helm-xmms2-pause, helm-xmms2-stop, helm-xmms2-next, helm-xmms2-prev that do the obvious