Complex sentence: She later began her American debut with the St. Louis Symphony, performing a recital of Beethoven's Ninth Symphony; followed by her 1962 European debut at the Concertgebouw in Amsterdam, thereafter touring all European countries in recitals.
Split into simpler sentences: She later began her American debut with the St. Louis Symphony, performing a recital of Beethoven's 9th. Followed by her 1962 European debut at the Concertgebouw in Amsterdam, thereafter touring all European countries in Recitals.