I am a composer and would like to sell music assets and packages in the marketplace. Is this allowed?
Hey, i know that there will be a sneaky Staff Member behind me, answering this as well, but i will still try to answer your question 
You want to sell your own made music on the marketplace? I would say yes, since there are a already alot of Sounds available to buy.
But, as i said above, i guess a Staff member will also answer this, so you could still wait for an official answer.