Sonification is broadly defined as the display of data as sound, and has been used in educational, scientific and industrial settings to explore, find and monitor patterns and changes in data. Sonification has also played a vital role in music composition as a technique that offers new methodologies for the creation and structuring of sound, and for the representation of non-musical matters in music. Although numerous examples of artistic sonification exist, the use of spectroscopic data in music composition has not yet been assessed systematically. Spectroscopic analysis is concerned with the interaction of electromagnetic radiation and physical matter. The portfolio explores the use of spectroscopic data in electroacoustic composition to find new methodologies for creating and structuring sound. It examines the role of spectroscopic data in acousmatic, audio-visual, and virtual reality works and investigates how electroacoustic compositions using spectroscopic data can be used to raise awareness of current environmental and socio-political challenges. The portfolio comprises seven electroacoustic works. Spin Dynamics is an acousmatic music composition that uses nuclear magnetic resonance (abbr. NMR) data as its only sound source. Inner Resonance explores the interplay between solid-state NMR sonification and the bass clarinet. Quantum combines NMR data with visual stimuli in an interactive virtual reality environment. The refugee crisis is contextualised in the audio-visual work Darkest Hour. Finland, as experienced by the Sea, presents pollution trends in the Baltic Sea using a mix of NMR, infra-red, and oceanographic data sonification. On the Extinction of a Species explores the sonification of DNA sequences of an extinct species to raise awareness of humanity's reckless treatment of its environment. Sound pollution and our relationship with technology are traced in 56Fe using the sonification of electron energy level data. The portfolio and written commentary contribute to the field of electroacoustic composition by presenting and evaluating methodologies for the sonification, framing, and presentation of spectroscopic data. Promising avenues of future work are discussed.