| Sasayaki | Felix Hess | 4×CD-R | 1 + 1 + 1 + 2 | | OP-0001 | |
| Aoi no Ue | Joji Yuasa | CD | 2 | | OPA-001 | |
| Music for Puppet Theatre of Hitomi-za | Joji Yuasa / Kuniharu Akiyama | CD | 10 | | OPA-002 | |
| Music for Tinguely | Toshi Ichiyanagi | CD | 3 | | OPA-005 | |
| Music Drama “Akai Mayu” (A Red Cocoon) | Makoto Moroi + Kuniharu Akiyama | CD | 6 | | OPA-003 | |
| Music For Theatrical Drama | Joji Yuasa | CD | 11 | | OPA-004 | |
| Music for Theatrical Drama | Joji Yuasa | CD + 8cm CD | 11 + 2 | | OPA-004 extra | |
| Lament for the Rise and Fall of the Elephantine Crocodile | Yoshi Wada | CD | 2 | | OP-0004 | 4560283210740 |
| Tape Works of Kuniharu Akiyama 1 | Kuniharu Akiyama | CD | 3 | | OPA-006 | |
| 秘蔵テープ作品集１ | 秋山邦晴 | CD + 8cm CD | 3 + 4 | | OPA-006 extra | |
| Electronic Field | Toshi Ichiyanagi | CD | 1 | | OPA-008 | |
| Experimental Music of Japan, Volume 1: Live Document “Hommage for Space” | Various Artists | CD + CD-R | 4 + 2 | | OPX-001 extra | |
| Off the Wall | Yoshi Wada | CD | 3 | | OP-0006 | 4560283210788 |
| Electronic Works Vol. 1 | Haruyuki Suzuki | CD | 6 | | OPX-002 | |
| Music for Experimental Films | Joji Yuasa | CD | 3 | | OPA-007 | |
| Drip Music | Toshi Ichiyanagi | CD | 1 | | OPA-009 | |
| Early Works & Live 1994–1996 | Tomomi Adachi | CD | 15 | | OPX-003 | |
| Earth Horns With Electronic Drone | Yoshi Wada | CD | 1 | | OP-0007 | 4560283210818 |
| Earth Horns With Electronic Drone | Yoshi Wada | 3×12" Vinyl | 2 + 2 + 2 | | OP-0007LP | 4560283219811 |
| Electronic Symphony No. 1 | Hiroaki Minami | CD | 5 | | OPA-010 | |
| Radiated Falling | Mamoru Fujieda | CD | 9 | | OPA-011 | |
| Radiated Falling | Mamoru Fujieda | CD + CD-R | 9 + 2 | | OPA-011 extra | |
| Experimental Music of Japan, Volume 4: Early Works 1983–1986 | Agencement | CD | 5 | | OPX-004 | 4560283218449 |
| Miniatures of Concrete Works | Joji Yuasa | CD | 16 | | OPA-012 | |
| Hosshin no Kizashi | Kazuya Ishigami | CD | 5 | | OPX-005 | |
| R.G.B. / Pre Optron 1999 | Atsuhiro Ito | CD | 6 | | OPX-006 | |
| Assemblage | Kazuo Uehara | CD | 7 | | OPX 008CD | |
| Kusabira | Makoto Moroi | CD | 2 | | OPA-013 | |
| Background Sound in Textile Pavillion of EXPO ’70 | Joji Yuasa | CD | 6 | | OPA-014 | |
| Early Works | Kazuo Uehara | CD | 4 | | OPA-016 | |
| John Cage Shock, Volume 1 | John Cage | CD | 3 | | OP-0008 | 4560283211044 |
| John Cage Shock, Volume 2 | John Cage | CD | 2 | | OP-0009 | 4560283211051 |
| John Cage Shock, Volume 3 | John Cage | CD | 3 | | OP-0010 | 4560283211068 |
| Event ’73 | Kazuo Uehara | CD | 4 | | OPA-015 | |
| Fragments of Sound, Figure of Music | Kenichi Kanazawa, Shinjiro Yamaguchi & Hiroyuki Ura | CD | 7 | | OPX-009 | 4560283218494 |
| Solo Performance | Kenichi Kanazawa | CD | 7 | | OPX-010 | |
| Music for Piano | Toshi Ichiyanagi; Takuji Kawai | CD | 8 | | OPX-011 | |
| Hommage to Home Electronics | Veltz | CD | 8 | | OPX-012 | 4560283218524 |
| Funakakushi | Toshi Ichiyanagi | CD | 2 | | OPA-017 | 4560283218203 |
| Echoes | Somei Satoh | CD | 2 | | OPA-018 | 4560283218210 |
| Kumo no Ito (The Spider’s Thread) | Hiroaki Minami | CD | 2 | | OPA-019 | 4560283218227 |
| Extended Voices | Toshi Ichiyanagi, John Cage, Takashi Matsudaira, Shigeru Matsui; Takashi Matsudaira | CD | 5 | | OPX-013 | 4560283218531 |
| a i sha | Akio Suzuki | 12" Vinyl | 3 | | OP-0013LP | 4560283218548 |
| Shikisokuzekuu-Kuusokuzeshiki | Toshi Ichiyanagi | CD | 2 | | OPA-020 | 4560283218234 |
| Environmental Music for Dining Room of Athletes’ Village in Tokyo Olympics 1964 | Kuniharu Akiyama | CD | 2 | | OPA-021 | 4560283218241 |
| Music for Piano | Yasumune Morishige | Reizen | CD | 7 | | OPX-007CD | |
| Live in Hong Kong | Yasumune Morishige & Reizen | CD | 1 | | OP-0015 | |
| Live In Hong Kong | Yasumune Morishige and Reizen | CD + CD-R | 1 + 2 | | OP-0015, OP-0015SP | |
| Live In Hong Kong | Yasumune Morishige & Reizen | CD + CD-R | 1 + 2 | | OP-0015, OP-0015SP | |
| Great White Light | Great White Light | 12" Vinyl | 2 | | OPS-001 | |
| Practical Concert | GAP | 2×CD | 2 + 1 | | OPA-022 | 4560283218258 |
| Computer Space | Toshi Ichiyanagi | CD | 6 | | OPA-023 | 4560283218265 |
| Reading-Affair | Kosai Hori | CD | 5 | | OPS-002 | |
| Early Electronic Works | Onnyk | CD + CD-R | 2 + 1 | | OP-0016, OP-0016 extra | |
| Early Electronic Works | Onnyk | CD | 2 | | OP-0016 | |
| Music for Film Genjitsu | Joji Yuasa | CD | 27 | | OPA-024 | |
| Music for Film Genjitsu | Joji Yuasa | CD + CD-R | 27 + 14 | | OPA-024SPA | |
| Night Event at Festival Plaza in EXPO ’70 | Yori-Aki Matsudaira | CD | 2 | | OPA-025 | 4560283218289 |
| Night Event at Festival Plaza in EXPO ’70 | Yori-Aki Matsudaira | CD + CD-R | 2 + 5 | | OPA-025, OPA-025 extra | 4560283218289 |
| 冥界のへそ | 高橋悠治 | CD + CD-R | 5 + 1 | | OPA-026, OPA-026SP | |
| 冥界のへそ | 高橋悠治 | CD | 5 | | OPA-026 | |
| 実験音楽グループ アート・チクルスの知られざる活動 | アート・チクルス | CD | 17 | | OPA-027 | 4560283218302 |
| 実験音楽グループ アート・チクルスの知られざる活動 | アート・チクルス | CD + CD-R | 17 + 3 | | OPA-027, OPA-027 SP#2 | |
| ピアニスト・一柳 | 一柳慧 | CD | 3 | | OPX-014 | 4560283218579 |
| ピアニスト・一柳 | 一柳慧 | CD + CD-R | 3 + 2 | | OPX-014SP | |
| Early Sound Installations | Yoshio Uji-ie | 3×CD + CD-R | 8 + 4 + 4 + 2 | | OPA-028, OPA-028SP | |
| Early Sound Installations | Yoshio Uji-ie | 3×CD | 8 + 4 + 4 | | OPA-028 | |
