In 1989, Robert gave his first solo marimba recital at the Concertgebouw, Amsterdam. He has since appeared at world's most prestigious concert halls in London, Paris, Vienna, Madrid, Milan, Stockholm, Oslo, Tokyo, Beijing, Seoul, Toronto, Mexico City, New York, Chicago, and Los Angeles. Van Sice participated in a few significant international events, including Archipel, Ars Musica, Darmstadt International Summer Course for New Music, Norfolk Chamber Music Festival, Bela Bartok Festival in Hungary and the Ultima Festival in Oslo. The BBC, Sveriges Radio, NRK, Radio France, Westdeutscher Rundfunk, National Public Radio and other prominent stations around the world have frequently broadcasted his concerts.
As a guest soloist, Robert van Sice had been featured with London Sinfonietta, Ensemble Contrechamps, Ensemble L'Itinéraire, Amadinda Percussion Group, Kroumata Percussion Ensemble, Tambuco Percussion Ensemble, Percussive Rotterdam, So Percussion (comprised of his former students) and other prominent European new music groups. Mr. van Sice often appeared on stage with a pianist Yvonne Loriod, Olivier Messiaen's wife.
From 1988 to 1997, the musician directed the Europe's first diploma program for solo marimba at the Rotterdam Conservatorium and Darmstädter Ferienkurse. Robert returned to the United States in 1997 and became a director of percussion studies at the Yale University School Of Music. Van Sice also taught at Peabody institute and joined the faculty of the Curtis Institute of Music in 2008. Throughout his pedagogical career, Robert gave over 400 master classes at the Royal College of Music, London, Conservatorium van Amsterdam, Juilliard School, Eastman School Of Music, The Oberlin Conservatory Of Music, Universität für Musik und darstellende Kunst Wien, and other institutions in twenty-five countries.
For the past fifteen years, Van Sice has been designing a signature series of marimbas for Adams Musical Instruments in the Netherlands. He also developed a line of 17-inch yarn wound marimba mallets with Vic Firth.