Jeonja Gongbang (전자공방, "electronic workshop") is a South Korean band led by the drummer Yeo Jin-woo (여진우). Its releases are billed 전자공방 (JJGB), with JJGB the Latin abbreviation printed beside the Hangul name, and the Seoul Forest Jazz Festival's English pages call it Jeonja Gongbang, or Electronic Workshop in a page title. The festival introduces it as a team grounded in jazz that has absorbed the feel of electronic and club music. Its recorded output is five digital singles released between January and November 2021. There is no album or EP, no published biography, no formation date and no photograph of the band, so this is a short profile that says only what listings, release credits and the festival's own text support.

Melon and Bugs list three members: Yeo Jin-woo, a keyboard player who goes by Supersu (수퍼수), and a member billed Funkboy. The two later singles, Ad Astra and About Lost Things, carry a full credit list: produced and composed by Yeo Jin-woo, arranged by Jeonja Gongbang, all keyboards by Supersu, drums by Yeo Jin-woo, bass by Ko Dae-seung (고대승), recorded by Lee Pyeong-uk (이평욱), mixed and mastered by John Davis, with artwork by Son Jeong-gi (손정기). Ko is credited as the bass player but is not listed as a member by either service. The three earlier singles say only "all music by Jeonja Gongbang (JJGB)", with the same mixing, mastering and artwork credits. Bugs files Funkboy under jazz and R&B/soul, and Melon under jazz and acid, fusion and pop; no instrument or real name is given for him. The festival's 2025 page names four people with Instagram handles and no instruments: the vocalist Nan Ah-jin (난아진), Choi Kang-su (최강수), Lee Jun (이준) and Yeo Jin-woo. The handle printed beside Choi's name, supersu56, matches the stage name Supersu, but no source states outright that they are the same person, and nothing says who Lee Jun is in relation to the member called Funkboy.

The five singles are Sorry But I Can't (January 18, 2021), Illusion (March 15), Hangover (May 17), Ad Astra (August 16) and About Lost Things (November 30), each between 4:33 and 5:54 long. The first three were issued through the label ONGRAY with YG PLUS as distributor, and the last two with Purplepine Entertainment as distributor. On its YouTube channel the band numbers its first, second, third and fifth releases as albums in the teaser titles, while Bugs, Melon and Apple Music all list each one as a single. Each release carries a short note in Korean. Sorry But I Can't argues that it is fine to be a little selfish when it is for your own good; Illusion lists equations such as event not equal to memory and memory not equal to experience, names the Kanizsa triangle and calls the self an illusion; Hangover is about waking up unable to remember the night before and hoping the forgotten moments were happy ones; Ad Astra is the band's song about space, written after a film convinced its author that space would not be wholly beautiful, with a voice source credited to NASA and a nod to Brad Pitt's acting; and About Lost Things reflects on all the objects, days and moments a person loses without noticing.

The jazz festival booking is the band's one dated public appearance. The ninth Seoul Forest Jazz Festival was scheduled for September 19 to 21, 2025 in Seoul Forest, and the Kyunghyang Shinmun's sports edition listed "전자공방 X 난아진" in its report of August 5, 2025 on the festival's third lineup, among newer acts, describing it as an act crossing the border between electronic music and jazz. The festival page schedules the set for September 20, 2025, from 14:30 to 15:20, under the line "Jazz racing over the beat", and says the band would play a collaborative stage with Nan Ah-jin, with sensual melodies over solid grooves. That is a guest billing: neither Melon nor Bugs lists her as a member, and the festival's own text introduces her as the vocalist joining Jeonja Gongbang rather than as part of it.

Nan Ah-jin has her own recording history. Bugs lists her as a female solo singer who debuted in 2012, filed under ballad and R&B/soul, and her credits there include "Chase" on the soundtrack of the OCN drama Ten 2 (April 15, 2013) and "Lead" on the second soundtrack of the MBC drama Joseon Attorney (April 7, 2023). The label text for "Chase" calls her a jazz vocalist whose voice mixes jazz and soul, and says she is strongly supported by jazz fans in Korea and Japan; that is the label's own description. Apple Music spells her name Nan Ah Jin and the festival's English page prints Nanajin.

What could not be found: the year the band formed, its members' ages and hometowns, any album, any release after November 2021, any live recording, any interview, any review in jazz or music press, and any entry on Discogs. Bugs also lists a Yeo Jin-woo as a member of two other groups, Black Russian and Wave.

No interview or review describing the band's sound was found, so this section only reports how the band and the services label the music.

The festival calls the band jazz-based, absorbing electronic and club sound, and gave its 2025 set the title "Jazz racing over the beat". The services label the recordings differently: Bugs files the singles as electronic and electronic pop, with Ad Astra additionally tagged indie and indie electronic, and Melon and Apple Music both file them as electronica. No jazz publication was found that reviewed the releases. The jazz description therefore rests on the band's festival billing and one newspaper line, not on a body of recordings that critics have placed in jazz. The two singles that list players show a drums, keyboards and bass lineup, and Ad Astra credits a voice source to NASA. No source names the band's influences.