Spectromorphology is an approach to sound materials and musical structures which concentrates on the spectrum of available pitches and their shaping in time.
The concepts and terminology of spectromorphology are tools for describing and analysing listening experience. The two parts of the term refer to the interaction between sound spectra (spectro-) and the ways they change and are shaped through time (-morphology). The spectro- cannot exist without the -morphology and vice versa: something has to be shaped, and a shape must have sonic content. Although spectral content and temporal shaping are indissolubly linked, we need to conceptually to be able to separate them for discursive purposes - we cannot in the same breath describe what is shaped and the shapes themselves.
Each component of the term belongs to other disciplines (visual, linguistic, biological, geological), which is fitting since musical experience radiates across disciplines.
A spectromorphological approach sets out spectral and morphological models and processes, and provides a framework for understanding structural relations and behaviours as experienced in the temporal flux of the music. (Sources - Denis Smalley (1986). Spectro-morphology and Structuring Processes, in Simon Emmerson, ed. The Language of Electroacoustic Music. Basingstoke: Macmillan. Denis Smalley (1997). Spectromorphology: Explaining Sound-shapes. Organised Sound Vol. 2, No. 2. Cambridge: Cambridge University Press.)