Released on July 29, 2024, as the inaugural installment of Amazon Music's innovative Songline series—a platform dedicated to spotlighting artists' songwriting processes—Billie Eilish's Hit Me Hard and Soft Acoustic Session captures the Grammy-winning artist in a stripped-back, emotionally charged setting. Filmed in Los Angeles with a small, appreciative audience, the 24-minute special features Eilish performing acoustic renditions of four standout tracks from her third studio album, Hit Me Hard and Soft (released May 17, 2024, via Darkroom/Interscope Records): "Birds of a Feather," "Skinny," "Wildflower," and "L'Amour de Ma Vie." These versions emphasize the album's "soft" side, as Eilish described, highlighting her whispery, high-register vocals and the minimalist instrumentation—primarily acoustic guitar and subtle piano—co-produced with her brother and collaborator, Finneas O'Connell.

The session delves into the creative intimacy behind the album, which Eilish and Finneas crafted entirely in their Los Angeles home studio over sessions spanning late 2022 to early 2024. Interwoven with performances are candid interviews where Eilish reflects on the evolution of each song: "Birds of a Feather" started as a demo-y vocal loop she adored for its rawness; "Skinny" underwent endless tweaks to perfect its haunting introspection on body image and fame; "Wildflower" emerged from a late-night emotional purge about lost love; and "L'Amour de Ma Vie" balanced French-inflected romance with subtle electronic undercurrents in its original form. Eilish shares how these tracks embody the album's titular duality—punching with lyrical depth while caressing with sonic tenderness—bending pop, folk, and R&B without a single pre-release single to preserve the project's holistic narrative.

Exclusively available on Amazon Music (with clips teased on Eilish's YouTube channel @billieeilish), the Acoustic Session has amassed over 10 million streams by September 2025, resonating deeply with fans amid her ongoing Hit Me Hard and Soft: The Tour (launched September 29, 2024, in Quebec City and extending through November 23, 2025, in San Francisco, with added dates in Japan and a second North American leg announced May 19, 2025). Critics, including Rolling Stone, praised it for revealing Eilish's "most comfortable" singing style—soft, unadorned, and profoundly connective—noting her gratitude to the crowd: "I feel so honored to be singing with you guys." The special ties into broader promotions, like cryptic lyric billboards and the album's eco-conscious physical releases (recyclable vinyl via her official store), while subtly nodding to tour elements, such as acoustic guitar segments in the 360-degree stage shows produced by Moment Factory.