Further studies with Milton Babbitt, Luigi Dallapiccola, and Luigi Nono convinced him of the merits of serialism, which he incorporated into his compositional technique.
One can however label enharmonically equivalent pitches with one and only one name, sometimes called integer notation, often used in serialism and musical set theory and employed by the MIDI interface.
Though he studied with Vaughan Williams and Stanford at the Royal College, Jacob preferred the more austere Baroque and Classical models to the Romanticism of his peers, and stuck to this aesthetic even in the face of the trends toward atonality and serialism.
Drawing on jazz, serialism, musique concrete, and other avant-garde techniques developed by contemporary classical music composers such as Luigi Nono and Giacinto Scelsi, the group was dedicated to the development of new music techniques by improvisation, noise-techniques, and anti-musical systems.
With the growing popularity of minimalist music in the 1960s and 1970s, which often broke sharply with prevailing musical aesthetics of serialism and aleatoric music, many composers, building on the work of such minimalists as Terry Riley, Philip Glass and Steve Reich, began to work with more traditional notions of simple melody and harmony in a radically simplified framework.
He later studied orchestration with Norbert Rosseau, and serial technique and electronic composition with Gottfried Michael Koenig and De Meester.
Mariétan studied first at the Geneva Conservatory in 1955–60 with Marescotti, and later with, amongst others, Pierre Boulez, Bernd Alois Zimmermann, Gottfried Michael Koenig, Henri Pousseur, and Karlheinz Stockhausen, and his earliest works are squarely in the serialist camp (Muggler 2001).
The composers of the Second Viennese School also produced several prominent concertos: Alban Berg's Chamber Concerto for piano, violin, and 13 winds (1923–25), not fully serial but incorporating many elements of Arnold Schoenberg's new system; Anton Webern's Concerto for nine instruments (1931–34), originally intended as a piano concerto; Berg's important Violin Concerto (1935); and Schoenberg's own Violin Concerto (1935–36) and Piano Concerto (1942).
During his years as a graduate student, he wrote serial and non-twelve-tone works, such as the a cappella choral works "Dylan Thomas Settings" and "Illuminations" (Rimbaud), and throughout the remainder of the 1970s most of his works were twelve-tone.