Open a royalty statement for the first time and you'll probably see the same song listed twice, on the same date, from two different sources, for two different (usually tiny) amounts. That's not a duplicate or a mistake. It's two entirely different rights being paid out separately, for the exact same play.
Two rights, one song
Every recorded song carries two separate copyrights bundled into one experience: the right to reproduce the composition, and the right to publicly perform it. Streaming a song technically does both at once — the platform makes a copy of the composition to deliver it to you, and it "performs" that composition by playing it out loud. Those are legally distinct acts, collected by entirely different organizations, on entirely different schedules.
Collected in the US by the Mechanical Licensing Collective (MLC), and by equivalent bodies abroad. Pays out per stream, tiny amounts, often the slower of the two to arrive.
Collected by a Performing Rights Organization — BMI, ASCAP, or SESAC in the US, and their counterparts internationally (PRS, GEMA, SOCAN, and more).
Why this trips people up
Most new songwriters register with one PRO and assume that's the whole picture. It covers performance royalties, but mechanical royalties are a separate registration entirely, usually through the MLC if you're in the US. Miss that step and you're leaving real money unclaimed — not because anyone's withholding it, but because nobody told the right collecting body that the song exists.
A song streamed on Spotify in the US can generate a mechanical royalty from the MLC and a separate performance royalty from your PRO — same stream, same day, two different checks, two different payers. Neither one substitutes for the other.
What to actually check
If you're self-releasing music, make sure you're registered for both: a PRO for performance royalties, and the MLC (or your distributor's mechanical licensing service) for mechanicals. They're separate systems that don't automatically talk to each other, and being registered with one doesn't mean the other one knows your song exists.