Hae In Cho (조해인) is a South Korean jazz vocalist, composer and bandleader who has released two records under her own name: the EP Compromise (January 21, 2022) and the album Sight Beyond Sight (May 21, 2024). Her name appears in several romanizations. The Korea Herald wrote Cho Hae-in, the Poclanos artist page uses Haein Cho, the cover of Sight Beyond Sight reads Cho Haein, and her releases on Spotify, Apple Music, Melon and Genie bill her as Hae In Cho. She writes the music for her records, and on Compromise she wrote all the lyrics as well.

Almost nothing about her life before 2021 is published. No source located gives a birth date, a birthplace, or a school or teacher, and she has no entry of her own on Discogs, MusicBrainz, Wikidata or Wikipedia. What is documented is her work from 2021 onward, all of it in Korea, and that record is enough to place her in the country's jazz scene.

Compromise was recorded on August 24, 2021 at Eum Sound, with the recording, mixing and mastering done by Jiyeop Kim. The band is the pianist Mijung Lim (임미정), who arranged every track except the last, the guitarist Woon Gi Han, the bassist Inyoung Kim and the drummer Seongku Lee. Cho produced it, composed all four songs, wrote all four lyrics and is credited with the artwork. The tracks are "The Midnight Sun", "Waters", "Stormy" and "Start the Stomping Sound", about 23 minutes in all, and the last of them is a duet for voice and double bass. The release notes compare the tone of the opening track to Sarah Vaughan and describe "Stormy" as a scat showpiece.

In 2022 she began to appear on Korean stages. The release notes for her later album say she played the Lecture Concert at the Jazz Festa on Nodeulseom, an island in the Han River in Seoul, in April of that year, and appeared on the "jam session, vocal edition" of the EBS program Space Gonggam, where she played standards. On August 23, 2022 the Korea Herald named her quintet, and called her a newcomer jazz vocalist, among the acts opening the 19th Jarasum International Jazz Festival, which began on October 1 on Jara Island in Gyeonggi Province. The same release notes mention that Melon's Track Zero feature picked her in its female jazz vocal category.

Sight Beyond Sight followed on May 21, 2024. It has seven songs and runs about 38 minutes. Cho produced it and composed and arranged every song; the lyrics are hers, with contributions from Chris Varga and Junho Song (송준호). Her working band from Compromise returns in part: Mijung Lim on piano, Inyoung Kim on bass and Seongku Lee on drums, joined by the guitarist Younwoo Park (박윤우) and, as a guest, Donggi Kim (김동기) on tenor saxophone and clarinet. It was recorded at Eum Sound again, with Jiyeop Kim as engineer. Nearly half of the album is played as duets, among them "Goodbye" with Lim on piano and "Two People" with Kim on tenor saxophone, and the opening track, "For Someone's Night", is the only song with Korean lyrics.

The album drew notice from Korean jazz writers. A newsletter by the Jazz Docent looking back at the jazz albums of 2024, dated February 16, 2025, named it one of the two albums its author played most, called it the author's personal album of the year, and compared her deep, resonant voice to Dianne Reeves. The newsletter also noted that the all-original program stays close to the standard jazz idiom. The album was nominated for Best Jazz Vocal Album at the 22nd Korean Music Awards. The nominees were announced in February 2025 and the ceremony took place in Seoul on February 27, 2025. The category went to Nam Ye-ji for 오래된 노래, 틈.

She has not been quoted in the sources located on which singers shaped her, so this section sticks to what the records and the writing about them show.

Her singing is rooted in standard jazz vocals and extends into the modern idiom, a range the release notes describe as running from standards to modern jazz. Two comparisons recur: the release notes hear the poise and fullness of Sarah Vaughan, and the Jazz Docent hears Dianne Reeves in the depth of her voice. Both mention her scat, which the notes call well constructed and which is most exposed on "Stormy" and "No Problem".

As a writer she composes in forms that sit close to the tradition. "Mr. Tangerine" is built on a traditional swing feel, "The Meaning of Life" opens with a bass introduction before classical and acoustic guitars enter, and "Two People" is arranged without any chordal instrument, so that a single saxophone line and the voice together imply the harmony. "For Someone's Night" is the only song on Sight Beyond Sight with Korean lyrics. On Compromise she has described the songs as written at the forks in life where decisions force a compromise, which gave the EP its title.