Òscar has been commissioned among others by the Aldeburgh Festival, the Philharmonia Orchestra for its Music of Our Time series, the Orchestra of the Swan, the Valencian Music Institute, the Trio Rebec, the Sounds Underground Ensemble and Kontakte Percussió.

His music has been premiered at the Wigmore Hall, Royal Festival Hall, Queen Elizabeth Hall, Sir Adrian Boult Hall, Yale University's Sprague Hall and the Palau de la Música de Valencia; it has also featured in festivals such as the City of London Festival, Manchester QuartetFest, the European Congress of Conservatoires, ENSEMS-València, or the Encuentro Internacional de Compositores 2006 in Mallorca. In August 2006 he was invited to be resident composer with the Joven Orquesta Internacional Ciudad de Oviedo . His orchestral piece Le Vitrail Englouti was premiered by the Royal Academy Symphony Orchestra conducted by Daniel Cohen in a project mentored by Yan-Pascal Tortelier. More recently he was selected by the Yale University Composition Department to take part in a Cross-Atlantic Partnership project with the Royal Academy of Music, involving a concert in London and a guest visit and concert at Yale University , USA .

Oscar teaches composition, harmony, analysis, Music History and aural at the Yehudi Menuhin School and is invited regularly to teach at the junior departments of the Royal College of Music and the Junior Royal Academy of Music. He has been supported in his studies by a number of scholarships awarded by the Valencian Music Institute, the Spanish Ministry of Culture and the Arts and Humanities Research Council.