Beginning in the 1970s, and aided by the advancement and an increased prevalence of computers, spectral music emerged as an important development in twentieth century music. Spectral composers, as exemplified by Gérard Grisey and Tristan Murail, took the harmonic spectra of sounds as the fundamental materials of composition. The resulting music placed an emphasis on texture and gradually evolving forms. The generation of composers immediately following the spectralists assimilated their techniques into distinct and varying styles. Finnish composer Kaija Saariaho uses spectral techniques to create an aesthetic that generates form and progression from a sound/noise axis. In her piece Du cristal…à la fumée, a number of pendulum and half-pendulum gestures build up texture and form. The accompanying original composition Axiom Unearthed employs similar pendulum gestures and uses spectral techniques to generate melody and harmony in an aesthetic divergent from traditional spectral pieces.