An understanding of the structure of the music industry is essential for independent music makers.
The key components within the music industry are:
Artists and Composers
The creators and the ‘talent’, the people who perform and write the music that we all consume
Managers
The representatives who take care of the creators career and manage their business needs
Lawyers
The legal advisors who help negotiate deals for clients and ensure they have the protection they need in law.
1) Record Companies
The recordings rights owner who will market and promote (exploit) the artists releases and pay a royalty on sales
2) Publishing Companies
The composition rights owner who will collect performance income , mechanicals and try to secure synchronisations / covers and other opportunities for the songs
3) Distributors
Physical and Digital they are still relevant and important to an artist’s or labels sales. Distribution is changing and digital aggregators now play a more significant role in the supply chain but you still need to be visible and accessible to consumers.
4) Retail
The place people buy records and digital products have changed dramatically but ‘retail’ is still important to the music business. There are still major players in terms of retail e.g. I-Tunes.
5) Collection Societies
E.g. PRS / MCPS / PPL enforce and collect revenues generated from copyrights in recordings and compositions.
6) The Media
Print, radio, TV and the internet are the main channels that connect the performers and music with the consumer.
7) Live Music
The performance of live music is more important than ever and the significance of its revenue and supply chain is increasing.
Music industry structure flow chart

Source: http://www.planetoftunes.com/industry/industry_structure.htm
Other useful links
BPI Industry Maps - http://www.bpi-med.co.uk/