The MLC still has ~$170M in unmatched mechanical royalties sitting in limbo because nobody can figure out who wrote the songs

When the Mechanical Licensing Collective launched in January 2021 under the Music Modernization Act, streaming services transferred approximately $427 million (later adjusted to $397 million) in historical unmatched mechanical royalties — money owed to songwriters and publishers that the platforms had collected but could not distribute because they could not match sound recordings to the underlying musical works. As of the latest reporting, the MLC has distributed about $225 million of this amount (57%), leaving roughly $170 million still unmatched and undistributed. These are real royalties earned by real songwriters for real streams that happened between 2018 and 2020, sitting in an escrow-like holding pattern because the music industry's metadata infrastructure is too broken to connect songs to their creators. The human cost is concrete. A songwriter who co-wrote a track that was streamed 500,000 times on Spotify in 2019 may be owed several hundred dollars in mechanical royalties that have been sitting in the MLC's unmatched pool for over six years. They may not even know this money exists. Under the MMA, any remaining unmatched royalties will eventually be distributed through an 'equitable market share' process — meaning the money goes to publishers and songwriters based on their overall market share, not based on who actually earned it. In practice, this means Universal, Sony, and Warner's publishing arms will absorb the bulk of unclaimed songwriter money. The independent songwriter who actually wrote the song gets nothing; the major publisher who had nothing to do with it gets a market-share-weighted windfall. The root cause is decades of neglect in music metadata infrastructure. Song ownership information is fragmented across hundreds of publishers, sub-publishers, administrators, and PROs, each maintaining their own databases with their own formats, identifiers, and error rates. There is no single authoritative global registry linking ISWCs (song identifiers) to ISRCs (recording identifiers). When a streaming service receives a recording from a distributor, it often lacks the corresponding publishing metadata needed to pay the songwriter. The MMA attempted to solve this by creating the MLC, but the MLC inherited a mess that took decades to create. Meanwhile, new unmatched royalties continue to accumulate as the daily upload volume (106,000 tracks/day) far outpaces the industry's ability to register and link metadata accurately.