EP-4 has been played over 10 times on NTS, first on 23 July 2016. EP-4's music has been featured on 12 episodes.

Active in the Japanese underground rock scene, Kaoru Satou (voices, drums, percussion; also known as a member of タコ/Taco) was a regular customer at Club Modern, a discotheque in Kyoto. Intending to create 'cool, no-sweat funk' he formed techno/psychedelic outfit EP-4 with some friends - Banana Kawashima (keyboards), Tatsuo Kouki (guitars), Kiyoshi 'Sanjoh-Dohri' Isogawa (drums), Yung Tsubota (percussion), and Kou Sakuma (bass) - at Club Modern around June in 1980. They wanted to represent rock music in a 'extremely processed' manner, with voice effects, mechanical sound generation, etc. typical to the Japanese Club Music scene of the period. In early 1980s, EP-4 played gigs at Urban Synchronicity in Kyoto (1981), and an 'Emergency Landing' tour in some metropolises in Japan (1982). In 1983, their reputation as a seminal Japanese underground rock outfit was established at an event at the Scanning Pool.

In the same year, EP-4 intended to release an album 'Lingua Franca-1 昭和崩御 (Shouwa Hougyo),' through remarkably impressive (and eccentric) promotion … they pasted dozens of stickers with only 'EP-4 5.21' written on them at random all around Japan (there's rumors that on a TV program, a renowned singer wore a T-shirt with the sticker on). This phrase "EP-4 5.21," meant that EP-4's debut album would be released on May 21st, 1983. However, the initial release was postponed under pressure from the Japanese government because of the album's subtitle - 'Shouwa Hougyo' means 'Death for Emperor Shouwa.' The album was finally released with the replacement subtitle "昭和大赦" ('Shouwa Taisha' - Amnesty for Emperor Shouwa) later that year.

EP-4 gigged around Japan and released some cassette EPs but were disbanded in 1988. Tatsuo and Kiyoshi have sadly passed away.