Because Soundcloud likes to keep fucking their shit up, embeds are currently broken. You can listen to any song that's been previously embedded, but you cannot post any new music as your post will be blank like so, so you'll have to just post the links to your songs until this issue is sorted.
I'll try to investigate it when I have time. Problem is how many layers of lion shit it was to fix this last time... I have disabled auto-embedding for the time being, so that you can post your links still without them being mangled by the BBCode interpreter, so that can hopefully tide things over while I take a look at this BS more closely.
