The stated aim of the series was to highlight "50 singers who've made their mark internationally and across recorded history.
"[1] Focusing on music discovery, the NPR editors who compiled the list started with on-air and online solicitation of nominations, and later votes, as a first step.
They then put together a panel of music journalists, critics, and musicologists to discuss nominations and come to a rough consensus on fifty artists to highlight.
One method was to name singers who were well-respected within their own genre, but lacked widespread familiarity.
The panel aimed to identify great, but not universally recognizable, singers.