Music distribution means selling music, and the word "sell" is important. If you want to sell something, you have to have a product, right? You have to have customers, right? You want customers to know your product, right? You want customers to buy your product, right? The same goes for music publishing. Music itself expresses ideas (lyrics, themes, emotions, etc.), style (can be called genre, Genre, music genre, etc.), participants (singer, lyricist, composer, arranger, producer, musician, post-production) etc.)