Tracklist Hide Credits
| A | NightmareWritten-By – Arthur Brown |
| B | What's Happening |
Other versions
| Category | Artist | Title (Format) | Label | Category | Country | Year |
|---|---|---|---|---|---|---|
| 59 247 | The Crazy World Of Arthur Brown | Nightmare / What's Happening (7") | Polydor | 59 247 | Germany | 1968 |
| 59 247 | The Crazy World Of Arthur Brown | Nightmare / What's Happening (7", Single, Promo) | Polydor | 59 247 | Germany | 1968 |
| 421 414 | The Crazy World Of Arthur Brown | Nightmare / What's Happening (7") | Polydor | 421 414 | France | 1968 |
| DP-1615 | アーサー・ブラウン* | Nightmare = 悪夢 (7") | Polydor | DP-1615 | Japan | 1969 |
| 59 247, N H 59 247 | The Crazy World Of Arthur Brown | Nightmare / What's Happening (7", Mono) | Polydor, Polydor | 59 247, N H 59 247 | Italy | 1969 |
