Sounds interesting! I like that you have the big picture in mind and the goal to help independent music. I've looked into musiccoin but I'm just not really down with the whole pay to play thing.. Personally I feel like we should strive to find other ways to pay the artists. That's why I like Steem as an example that this might work. Here everyone can read all posts for free. Still, in theory, content gets curated and good artists and "talent scouts" gets rewarded.

This got me thinking though that this could pretty much be achieved with your proposal as well. If I would say upload doubles of every track on Soundcloud with only one using your musiccoin option and link to it from the free one. To let people choose.

What would make me start using this merged platform is probably if they included the option for them to automate this. So that I can upload one track and they make a copy of it. So that everyone can choose to play it the old school way OR the musiccoin way seamlessly. And also they have to show what gets played and tipped a lot to give the incentive for people to sign up for the addition. Personal opinions, hope the trip goes well!