Part of the Escola Coral of the Orfeó Català, it is made up of between thirty and forty boys and girls aged from eight to ten. Glòria Fernàndez is its conductor and Laia Armengol is the pianist. During their time in this choir the singers begin to work regularly on the rich repertoire for children's choirs and build up their commitment to the choir by attending two weekly rehearsal sessions. The singers are introduced to vocal technique by training their voice, as well as teaching the body posture and awareness of breathing needed to sing. They combine rehearsals with two sessions a week on musical language to learn the basics of reading and writing music.

They appear regularly in concerts at the Palau de la Música Catalana alongside the other choirs of the Escola Coral, and also pursue their own activities within the Palau and outside, taking part in exchanges with other Catalan choirs.

Recently, in 2024, one highlight was the participation in March in the Palau Vincles Concert, featuring the premiere of Una cantata diferent by Adrià Aguilera. The piece was also performed solo at the Fabra i Coats Creation Factory, as part of the Ciutat de Clàssica 2024 festival. There was also a performance in the Foyer of the Palau, within the framework of the 69th Maria Canals International Music Competition in Barcelona, and a concert at the Gent Gran Gràcia senior residence, conducted by principal conductor Glòria Fernàndez, as part of Clàssica a la Platja–Regata Cultural. In May, the choir also took part in the concert Cuques de llum, with works by Marc Dalmases, alongside the Cor Petits of the Orfeó Català and the SCIC Choirs. Both choirs, led by their principal conductors, Glòria Fernàndez and Mercè Pi, performed together on December 18 at the 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 Cor Mitjans, together with the Cor Petits of the Orfeó Català, presented in May the cantata De qui és el bosc?, with music by Josep Ollé and a libretto by Marc Donat.

During the 2025–26 season, the Cor Mitjans, along with the Cor Petits of the Orfeó Català and the Coral Xiquets of the Orfeó Lleidatà, will present in June 2026 Opereta ecològica by Alberto Grau.