Go with your gut feeling; What feels like spamming, is most likely spamming :) Spamming at social networks where money is not involved, is already annoying. Spamming at social networks where money IS involved is not only annoying but it is stealing money in the end and many curators don't like that; Also hivewatchers not.

I'm not saying you can't re-use some content, but the majority of a post shall be unique in one way or the other, otherwise its gonna be spamming quickly. Publishing at 3Speak, I think it is then not possible to add a community other than whatever 3Speak pushed the content into.

My suggestion would be to share you YouTube so you have freedom in selecting the right community. Its not that I'm the MOD of one of the music communities that I advise you to look at this community: /trending/hive-193816 its a music community in the making, more or less music across the board.

Of course you can explore other communities as well, and I invite you to do so. But I would suggest to always create unique posts for each publication in whatever community you do this.