Some sources say the deal could be for Recognition Music's entire portfolio. Recognition Music Group Trending on Billboard Sony Music Group’s publishing arm is negotiating with Blackstone in what could be a deal to acquire all of Recognition Music Group’s publishing assets, according to sources. The move comes on the heels of two prior asset sales by Blackstone to Sony, and also after the private equity firm assigned Sony Music Publishing to be the primary administrator of its song catalog.   Since 2017, Blackstone has amassed a portfolio of an estimated $4 billion in music assets, acquired by two of its separate investment teams. Beginning in 2021, a London-based Blackstone investment team spent around $800 million on music assets via Hipgnosis Songs Capital, and bought the administration arm of Hipgnosis Songs Management, before subsequently acquiring the publicly traded music catalog assets of Hipgnosis Songs Fund for $1.6 billion in April 2024.…