soundcloud is a website http://www.soundcloud.com where you can host your audio. You can then embed your sound cloud hosted audio directly on the songstuff boards using the insert media button on the Songstuff post editor. It's a good site in terms of audio hosting, although I am less into other aspects of the site. Way too much back patting in terms of comment.
btw You can also directly attach audio to your posts on Songstuff using the attach file option, or upload your audio into your Songstuff gallery. Songstuff isn't intended as an audio host in the way that Soundcloud is, this is just a capability we provide to aid critique where as it is the core function of soundcloiud.