The works of Award Winning Spanish composer Juan J. Colomer (aka Juanjo Colomer), have been performed by the San Francisco Symphony, Simón Bolívar Symphony Orchestra, Russian National Orchestra, Los Angeles Philharmonic, National Orchestra of Spain (ONE), Arena de Verona Orchestra and Choir, Vienna Symphony, Orquestre de Paris, the Budapest National Orchestra, Seoul Symphony Orchestra, Orchestra of the Valencian Community (Les Arts), San Diego Symphony, Orquesta de RTVE, Attacca Quartet, Liceo Orchestra (Barcelona), National Symphony of Ecuador, Spanish Brass, Galicia Symphony (OSG), Central Germany Broadcast Orchestra & Chorus (MDR), Los Angeles Children Chorus (LACC), and many others throughout the world at prestigious halls like Carnegie Hall (NY), Tchaikovsky Concert Hall (Moscow), Elbphilharmonie (Hamburg), Teatro Real (Madrid), Walt Disney Concert Hall (Los Angeles), Teatro Teresa Carreño (Caracas), The Rady Shell at Jacobs Park (San Diego), or Adrienne Arsht Center (Miami).

Ha has collaborated with such artists as Plácido Domingo, James Levine, Christian Lindberg, and Mikhail Pletnev.

In 2008, the CD “Spanish Passion” by Plácido Domingo, featuring orchestrations by Colomer, won a Latin Grammy for Best Classical Album.

His ballet “Sorolla” commissioned by the National Ballet of Spain, premiered June 12th, 2013 in Madrid (Naves del Matadero).

His second opera "El Pintor" (The Painter) based on Picasso, with libretto by Albert Boadella, was commissioned by Teatro Real (Madrid) as part of the 200 year anniversary celebration and premiered in 2018.

In 2024, his CD “Symphonic genesis” was nominated for Best Classical Album & Best Instrumental Album by the Music Academy of Spain.