K-pop phenomenon BTS will drop a new album, "Map of the Soul: 7," Friday evening, rocking the world music scene once again.

The upcoming 20-track album is the second part of its "Map of the Soul" album series, following "Map of the Soul: Persona," released in April last year.

Like its predecessor, "7" is a soul-searching musical journey, inspired by concepts developed by Swiss psychiatrist Carl Jung like the persona.

The new album is led by main track "ON," a captivating, powerful hip hop number whose 30-second preview audio was released early Friday morning via video-sharing platform TikTok.

Videos of fans' wild reactions to the sample flooded TikTok using the hash tag "onchallenge" within an hour of the preview's release.

"ON" explores BTS' devotion and sense of being artists, developed and refined through the band's eventful seven-year career.

BTS prereleased three songs from the album: "Interlude: Shadow," "Outro: Ego" and "Black Swan." The band premiered the latter on American TV show "The Late Late Show with James Corden" last month.

Including the prereleased tracks and the main song, the new album has 15 brand new numbers, like "Filter," "UGH!," "00:00 (Zero O'Clock)," "Inner Child," "Moon," "Louder than Bombs" and "We Are Bulletproof: The Eternal."

"Filter" is a solo effort by member Jimin that delves into Jimin's growth from K-pop trainee to adult. On his own solo track, "Inner Child," V talks about an ordeal he faced, while Jin expresses his love for BTS fans -- the "Army" -- in "Moon."

Pop star Troye Sivan helped produce "Louder than Bombs."

BTS will separately release a special digital version of "ON" featuring Australian singer-songwriter Sia on Friday evening.

The album also contains five hit songs from "Map of the Soul: Persona," including "Boy With Luv," "Make It Right" and "Dionysus."

Along with the album, the septet will release a "kinetic manifesto film" for "ON" before appearing on American TV program "The Today Show" on Friday (US time).

The band will then fly back to Seoul to host a global press conference in the South Korean capital on Monday. 

Preorders for "Map of the Soul: 7" had reached 4.02 million copies as of Monday, a record in South Korea. (Yonhap)