The metaphors of 运动 and growth are 适合 ways of considering a time-based 艺术 like 電聲學/电声学 樂/乐 传统 概念 of 节奏 are inadequate to 描述 the often dramatic 曲线 of 電聲學/电声学 姿态 and the 内在 运动 of 质地（纹理、织体） which are 表示 through a wide variety of spectromorphologies Since 运动 and growth have 频谱 曲线 they are set in 频谱 空间 Therefore their occupancy of 频谱 空间 and their 频谱 密度 will be 重要 additional qualifiers In addition 运动 and growth can be enhanced by actual 空间 分布 运动 and growth have 指向 tendencies which lead us to 期望 可能 outcomes and they are helpful guides in attributing 结构 功能（函数） Condensed from Denis Smalley 1997 频谱形态 Explaining Sound-shapes Organised 声波 Vol 2 No 2 Cambridge Cambridge University Press