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

His music has been premiered at the Wigmore Hall, Royal Festival Hall, Queen Elizabeth Hall, Sir Adrian Boult Hall, Yale University's Sprague Hall, Palau de la Música de Valencia, and the Auditorio de Galicia with the Real Filharmonia de Galicia Orchestra; it has been radio broadcasted in Spain, Mexico and the USA; and 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. 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. He was selected by the Yale University composition faculty to take part in a Cross-Atlantic Partnership project in 2007, involving a concert in London and a guest visit and concert at Yale University , USA . He has been resident composer of the Joven Orquesta Internacional Ciudad de Oviedo (2006) and in Cove Park (2008) .

Oscar teaches 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 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.