Like every other orchestra, the USO has to rehearse for their concerts. . These rehearsals are every Wednesday from 7:45 pm until 10:30 pm. The rehearsels take place in het STUK (Naamsestraat 96). During both the examination period, the rehearsals are put on hold to allow the members of the orchestra to fully prepare for their exams.
When the program is hard, or the concerts fall early in the year, the USO also often rehearses on Sunday evenings.