Italian composer Giacinto Scelsi (1905-1988) was largely unnoticed during his career even among contemporary music circles. His music enjoyed a revival later in his career thanks in part to performers like French double bassist Joëlle Léandre who championed his work. Scelsi was a classic eccentric, an introspective and introverted artist with a Promethean disposition to life and music. His signature work, Quattro Pezzi, is a transcribed improvisation of one-note variations and manipulations that probably echoed his combined experiences as an improviser in his childhood and as a psychiatric ward patient whose "therapy" included one-note improvisations at a piano.
Baguyos, Jeremy C., "Review of Giacinto Scelsi, The Works For Double Bass" (2008). Music Faculty Publications. 14.