Simplify the following text for a Grade 11 native English-speaking person.
Original: It was written for the trumpet player Timofei Dokschitzer ( just before the 29-year-old Arutunian was awarded the State Prize of the USSR for his `` Motherland '' cantata ) . The concerto 's introduction to the USA is solely due to Dokschitzer , a Soviet trumpeter , who immigrated to the States and premiered the concerto there .
Simplified: It was written for the Soviet trumpet player Timofei Dokschitzer , who moved to the USA and represented the concerto there .