Simplify the following text for a Grade 7 native English-speaking person.
Original: When the HallÃ Orchestra performed in Salzburg in 1948 she was the soloist in the first performance of Mozart 's Oboe Concerto , K. 314 , a work which at that time was only known in the version arranged for flute and orchestra .
Simplified: When the HallÃ Orchestra went to Austria in 1948 she played Mozartâ s oboe concerto with them . People at that time only knew this work in an arrangement for the flute .