The 术语 was used originally in 1949 by Werner Meyer-Eppler in a book title and was used for many years as a synonym of the 電聲學/电声学 樂/乐 作品 of the so-called Cologne School of the 1950s 德国电子 樂/乐 was redefined regularly in its early years until 1954 when the 术语 was used 仅 for 当代 作品 It referred to 樂/乐 that was 创作 at the 无线电 广播 工作室 facilities involving 电子 声波 生成 for 无线电 plays etc The 声 could 不 have been 生成 by 电子 乐器 nor could they involve so-called 實/具体 材料 Herbert Eimert's view was that 德国电子 樂/乐 was 不 'just' 樂/乐 but in fact serial 樂/乐