Simplify the following text for a Grade 7 native English-speaking person.
Original: Masterpieces were written by Edward Elgar ( a violin concerto and a cello concerto ) , Sergei Rachmaninoff and Nikolai Medtner ( four and three piano concertos , respectively ) , Jean Sibelius ( a violin concerto ) , Frederick Delius ( a violin concerto , a cello concerto , a piano concerto and a double concerto for violin and cello ) , Karol Szymanowski ( two violin concertos and a `` Symphonie Concertante '' for piano ) , and Richard Strauss ( two horn concertos , a violin concerto , Don Quixote â '' a tone poem which features the cello as a soloistâ '' and among later works , an oboe concerto ) .
Simplified: This kind of concerto was called a concerto grosso .