The mechanical royalty rate varies month to month based on how many total streams occur in Spotify in the US and how much money Spotify in the US has made in any given month.

I verified the math using my own assumptions starting with 1000 subscribers that generate $10 per subscriber per month ($10,000 per month). I assumed that 900 of those users streamed 2000 songs per month, and listened to artist “A” 80% of the time and artist “B” 20% of the time, the other 100 users streamed 200 songs per month and only listened to artist “B”.

The current method calculates the revenue distributed to arts "A" and "B" as a ratio of the number of streams to the total number of streams. This method pays a monthly sum of:

• $9,988.90 to artist “A”
• $11.10 to artist “B”

If the revenue from the money each user payed for a subscription got distributed among the artists the individual subscriber listened to, this method would pay out a monthly sum of:

• $7,200 to artist “A”
• $2,800 to artist “B”