Solar of MAMAMOO has announced the release of a new single, titled “To My 20s,” in collaboration with singer and harmonica player Harim.

“To My 20s (Harmonica. Harim)” will be released on November 12, 2026. It was unveiled on October 29 via a teaser poster, which depicts a punctured envelope. Words can be seen through some of the holes, though what they refer to is currently unclear – driving curiosity and anticipation.

Within this new single, singer-songwriter Harim will provide a harmonica performance that makes up part of the instrumental. Harim is recognised as a pioneer of world music in South Korea, his ability to play a variety of instruments allowing him to harness elements from different global genres. He has been celebrated for incorporating jazz, folk and African rhythms into conventional Korean ballads, and is exceptionally known for his work with the harmonica.

Harim’s harmonica playing will bring a unique sound to Solar’s single, allowing it to stand out in the industry and also perhaps creating a more emotive, personal tone. The title “To My 20s” indicates that the song is likely to be deeply personal, addressing not only Solar’s past and ideas surrounding time but specifically the period she has spent with MAMAMOO, having debuted when she was 23.

“To My 20s” will be Solar’s first solo project in approximately one year and seven months, following the release of her second single album WANT in April 2025. During that time she has been carrying out a wide range of activities in Korea and overseas, primarily as part of MAMAMOO. The group reunited this year with the 12th anniversary special single album 4WARD and its ensuing world tour, which began in Seoul in June. So far, MAMAMOO have performed across Asia, North America, and Australia, and will wrap up the reunion tour in Taipei on November 28 and 29.

As the ‘MAMAMOO 2026 WORLD TOUR [4WARD]’ approaches its conclusion, “To My 20s” will give Solar an early push back into the industry as a soloist. It is not yet clear whether Solar intends to make a full return following the release of this single, but its timing suggests that there may be a chance of more solo music from Solar soon once her current activities with MAMAMOO have been completed.

Solar already has several popular songs making up her solo discography – including “HONEY,” “SPIT IT OUT,” and “Adrenaline” – and “To My 20s” will hope to add to that list using the increased visibility MAMAMOO’s reunion has given her.

“To My 20s (Hermonica. Harim)” will be available on global streaming platforms on November 12, 2026. A busking event in Sinchon, Seoul is also scheduled for November 6.