Just for starters, Dsound is on the Steem bockchain, so you can get rewarded for your content. It also is an up and coming community, effervescent with new and original musick. I love it! Musicoin is also based on a blockchain, its very own, and rewards artists as well, through the p-p-p (pay per play) system, which is also awesome. Soundcloud offers none of that. Make your own conclusion ;)