For more than a decade, the works of Roberto Sierra have been part of the repertoire of many of the leading orchestras, ensembles and festivals in the USA and Europe. At the inaugural concert of the 2002 world renowned Proms in London, his Fandangos was performed by the BBC Symphony Orchestra in a concert that was broadcast by both the BBC Radio and Television throughout the UK and Europe. Sierra's numerous commissions include works for many of the major American orchestras as well as ensembles in Europe. International ensembles that have performed his works include the orchestras of Philadelphia, Pittsburgh, Atlanta, Houston, Minnesota, Dallas, Detroit, San Antonio and Phoenix, as well as by the American Composers Orchestra, the New York Philharmonic, the Los Angeles Philharmonic, the National Symphony Orchestra, the Kronos Quartet, Continuum, England's BBC Symphony, Royal Scottish National Orchestra, the Tonhalle Orchestra of Zurich, the Spanish orchestras of Galicia, Castilla y León and Barcelona, and at Wolf Trap, the Santa Fe Chamber Music Festival, Festival Casals, France's Festival de Lille, among others.
Recent commissions include: Concerto for Orchestra for the centennial celebrations of the Philadelphia Orchestra commissioned by the Koussevitzky Music Foundation and the Philadelphia Orchestra; Concerto for Saxophones and Orchestra commissioned by the Detroit Symphony Orchestra for James Carter; Fandangos and Missa Latina for the National Symphony Orchestra In Washington DC; Sinfonía No.