Composer and instrument inventor Harry Partch (1901-1974) is one of the pioneers of 20th-century experimental instrumentation, known for writing and playing music on incredible custom-made instruments like the Boo II and the Quadrangularis Reversum, and laying the foundations for many of today's most creative experimental musical instruments.
In this Universal Newsreel footage from the 1950s, Partch conducts a student music performance on his instruments, built with insights from atomic research and Partch's 30-year obsession with finding the elusive tones that exist between the tones of a regular piano. The setting is Mills College in Oakland, CA. The unorthodox orchestra performs music tuned to the 43-tone scale Partch invented, rather than the usual 12-tone, even though individual instruments can only play subsets of the scale.
For more on Partch's genius and seminal innovation, see his excellent 1949 meditation, Genesis of a Music: An Account of a Creative Work, its Roots, and its Fulfillments.
Maria Popova is the founder and editor in chief of Brain Pickings, a curated inventory of cross-disciplinary interestingness. She writes for Wired UK, The Atlantic and DesignObserver, and spends a great deal of time on Twitter.