How do you design an ER diagram for a database to store music album information that includes:

• A music album has a title, year of release, total running time, one or more artists, and list of songs.
• Each song has a lead artist and may have a list of additional artists. Each song has a list of other associated people such as mixer, mix engineer, keyboards, guitar, etc. Each song has a genre, running time, and lyrics. Each song can be associated with many albums, but needs to be associated with at least one.
• Each person has a first name, last name, and nickname.

What are some assumptions made to specify the structural constraints in this diagram?