Sometimes we need to step-back and have a music business 101 post. This link will take you to a summary on the four primary royalty streams in music publishing: mechanical, print, synchronization and performance royalties.
This link is to a chart on the income flow related to a recording artist.
Both documents cover the basics and are a good place to get started. Be looking for Texas music lawyer Tamera Bennett's subsequent post on the basic flow of record label/artist royalties when an independent record label uses a digital aggregator to make tracks available from retailers such as iTunes and Amazon.