The Making of ‘Birds of a Feather’: How Billie Eilish and Finneas Labored Nearly a Year on Their ‘Outlier’ Track, Then Let the Audience Discover It

variety.com:

Chris Willman Senior Music Writer and Chief Music Critic When Billie Eilish chose “Happier Than Ever” as the title of her previous album, you didn’t have to look far past the straight-faced album cover to find levels of irony in that.

She didn’t completely put on a happy face for this year’s full-length follow-up, “Hit Me Hard and Soft,” either. But one track, “Birds of a Feather,” did find Eilish basking in something very close to sunlight, with its pretty, percolating feel and nearly out-of-character romantic optimism.

When the ”Hit Me” album first landed, fans drove three tracks into the upper ranks of the Billboard Hot 100 (also including “Lunch” and “Chihiro”).

But it’s the feather-light touch of “Bird” that stuck around longest and became her biggest hit to date, as well as landing Grammy nods for record and song of the year and pop solo performance.