Complex sentence: During his studies he won numerous piano competitions, including the Kosciuszko Chopin Competition in 1984, the Music Teachers National Association Competition in 1984 and the American Pianist Association Fellowship (formerly known as the Beethoven Foundation).
Split into simpler sentences: During his studies he won numerous piano competitions, including the Kosciuszko Foundation Chopin Piano Competition and the Music Teachers National Association Competition, both in 1984. He was awarded the American Pianist Association Fellowship (formerly known as the Beethoven Foundation).