Distributors do just that. They distribute your music to every major digital music platform like Spotify and Apple Music. There are lots of great options. You can read a pretty lengthy comparison here if you're so inclined.
I personally use DistroKid and I've tried most other distributors. You can upload unlimited music for around $30/year and they take 0% of your royalties. While they aren't great at focused customer support, they have the best features in my opinion.
One of the biggest reasons I stick with DistroKid is for the ability to easily split royalty percentages to various people on your team whereas this functionality is not an option on other platforms. This eliminates an incredible amount of administrative work for the artist. LANDR would come in a close second, if not only for their prompt customer support. Regardless of what you choose it's pretty amazing that artists can easily upload their music to everywhere music is listened.
I have had my brain jumbled countless times trying to understand the spider-web of music royalties. I won't attempt a poor man's explanation of it here, but, I'll let you know the services I use to collect all the royalties you should be collecting as an independent artist.
First and foremost, your music distributor will collect the bulk of your royalties. This is what I call the master royalty. You might have heard, "Do you own the master?" This is in essence referring to the rights of the recorded song. Artists with big labels often don't own their own masters, which, is a shame. You should own your music; not the overlords.
To date, I have only shared a percentage of this royalty with my producer or an artist that features on a song. I once heard a pianist demanding 40% of the master royalty for playing on a song."You know you're not Elton John, right?" would've been my response. Money can be a paralyzing subject especially for altrustic artists; pour some hyper-spirituality in that cocktail and you've got the recipe for an awkward time.
The elephant in the room is that many artists barely make enough to buy a BigMac with the current payout per stream on Spotify being one third of a penny (~1,300 Spotify streams equals a BigMac). I do not advise eating BigMacs.
With that being said, the amount of green paper that a royalty percentage translates to varies drastically depending on how many times a song is streamed on music platforms. For example, if you gave your producer 25% of the master royalty on a song that got one million streams, they would make about $750. One million streams sounds like big bucks but your landlord won't accept that as rent. This is often why musicians and producers just charge an up-front dollar amount in exchange for their talent.
Whether you pay your people a percentage of the royalty, a one-time dollar amount, or a mix of both, is completely up to you and there isn't necessarily a one-size-fits-all. Speaking of spirituality, I pray about what percentages to give and prefer to err on the side of generosity; Better to be a poor friend than a lonely Scrooge. Beware: many people-pleasers have gotten taken advantage of along those lines. You should also be familiar with industry standards. If you have absolutely no idea, you can ask me and I'll give you my two cents (pun).
While your music distributor will collect all the master royalties, there are, to my knowledge, three other resources you should be using to collect all the other royalties owed you. Please note that this information applies to US-based artists.
SongTrust is a publishing administrator that registers your songs with global performance and mechanical organizations. They collect all of the publishing royalties your songs earn. SongTrust has been my second highest source of royalty income behind the master royalty.
ASCAP is a performance rights organization (PRO) that collects songwriting royalties. Artists are poor but songwriters beg for crumbs from the artist's table. Songwriting royalties are much, much less than every other royalty.
SoundExchange collects digital performance royalties which come through services like Pandora and SiriusXM.
more info on the way
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Do I need to run ads?
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Should I sign to a label?
Do I need to sell merch?
And things like that.