Part of the Escola Coral of the Orfeó Català, it is made up of about twenty boys and girls aged six and seven. This is a stage at which the singers begin their training in the world of music and the voice. On the basis of songs, exercises and games they seek and work to extend their voice, lightness, tune and aural recognition through listening and imitation.

This is the time when the children are educated in rhythm, beat and musical expression through singing, dancing to and acting out songs, and the singers begin to familiarise themselves with breathing and awareness of their body.

They work divided into two groups by age: Petits 1, aged six, and Petits 2, aged seven, receiving a specific musical training precisely attuned to their level of maturity. These sessions take place at the Palau de la Música Catalana and the choir has the chance to perform three times a year on stage with the rest of the Escola Coral choirs: at the Concert d’Any Nou, the end of course Concert and the Concert de Sant Esteve. Activities are also organised outside the Palau, as well as concerts, exchanges with other choirs and a working weekend.

In 2023, they will perform at the Palau alongside the Children's Choir of the Orfeó Català with the program “From Night to Day”, featuring works by Brahms, Rutter, Pastrana, and Luboff, among others, with stage direction by Dani Coma. They will also present the Chiaroscuro concert, together with the other ensembles of the Escola Coral, all conducted by Basilio Astúlez.

In 2024, the Petits Choir of the Orfeó Català gave a performance in March at the Foyer of the Palau as part of the 69th Maria Canals International Music Competition of Barcelona. In May, they performed the concert Cuques de llum, with works by Marc Dalmases, together with the Mitjans Choir of the Orfeó Català and the SCIC Choir. In June, they performed at the Fort Pienc retirement home, conducted by Gemma Tatay, as part of Clàssica a la Platja – Regata Cultural. Additionally, the Petits Choir, alongside the Mitjans Choir, conducted by their directors Glòria Fernàndez and Mercè Pi, performed together on December 18 at Moll de la Fusta in Port Vell, in a Christmas carol concert as part of Nadal al Port organized by the Barcelona City Council. In 2025, the Petits Choir, together with the Mitjans Choir, presented in May the cantata De qui és el bosc? (Whose is the forest?), with music by Josep Ollé and a libretto by Marc Donat.

In the 2025–26 season, the Petits Choir together with the Mitjans Choir of the Orfeó Català and the Coral Xiquets of the Orfeó Lleidatà will present in June 2026 the Opereta ecològica (Ecological operetta) by Alberto Grau.