Three discs, three distinct worlds - each one a landmark. Vol. 5 of Earle Brown's Contemporary Sound Series may be the most dramatically varied installment in the entire programme, arcing from the handmade electronic circuitry of four American mavericks to one of the great piano sonatas of the 20th century, and closing with the golden tone of the most celebrated flutist of the post-war avant-garde.

The first disc is Electric Sound, the only album the Sonic Arts Union ever released as a group. Originally issued on Mainstream in 1972, it documents the four composers who, from 1966 to 1976, collectively redefined the possibilities of live electronic music in America: Robert Ashley, David Behrman, Alvin Lucier, and Gordon Mumma. Each contributes a single work - Lucier's Vespers, a piece for performers navigating darkness using echolocation devices; Ashley's Purposeful Lady Slow Afternoon, a quietly devastating text-sound composition; Behrman's Runthrough, built on homemade circuitry and feedback systems; and Mumma's Hornpipe, in which a French horn interacts with a wearable, custom-built electronic processor. Recorded at the Rose Art Museum at Brandeis University, these are not studio artifacts but traces of a living practice - music inseparable from the physical gestures and improvised decisions that brought it into being.

The second disc preserves Aloys Kontarsky's monumental reading of Charles Ives's Piano Sonata No. 2, "Concord, Mass., 1840-1860" - one of the first European recordings of this towering, unwieldy American work. Originally issued by Time Records in 1962, the performance is raw, deeply considered, and utterly committed - the German pianist bringing a rigorous structural intelligence to Ives's layered quotations, hymn fragments, and philosophical density. A rare document of a European avant-gardist grappling with the radical otherness of Ives's vision.

The third disc belongs entirely to Severino Gazzelloni, the Italian flutist whose virtuosity and fearless appetite for new music made him the dedicatee of works by Luciano Berio, Pierre Boulez, Bruno Maderna, and Igor Stravinsky. Accompanied by Kontarsky on piano, Gazzelloni performs works by Franco Evangelisti, Niccolò Castiglioni, Berio, Olivier Messiaen, Yoritsune Matsudaira, and Maderna - first recordings in every case. Berio's Sequenza I, written specifically for Gazzelloni, is captured here in the hands of its original interpreter - an indispensable historical document. Messiaen's Le Merle noir, all birdsong transcription and rhythmic asymmetry, sits alongside Maderna's luminous Honeyrêves and Matsudaira's Somaksah, drawing a vivid map of the international flute repertoire at the height of post-war modernism.

Packaged in a box with three CDs in jewel cases and four booklets containing liner notes in English, German, and French. Digitally remastered by Udo Wüstendörfer under the auspices of the Earle Brown Music Foundation.