Use several sources when creating a synopsis of a performer's biography. Note whether they agree on basic facts like birthdate, birthplace, date of death. Also compare what the articles choose to emphasize, gloss over, or not mention at all.
Many biographies you come across will include a separate discography. We're lucky enough to have entire discographies devoted to a single performer: you'll find those in the ML156 section of the library, or by searching the library catalogue for your performer + discography. Some discographies online continue an earlier print version. There are also general websites listed below that may have good information.
If there are entire books written on the performer you're interested in, you'll find citations in the encyclopedia articles. You can also search the library catalogue with the following search template: "performer first name last name" biography (it's important to put quotes around the performer's name so it's searching as a phrase).