Complex sentence: Cook had performed professionally as a student and made his debut in 1889 in Washington, DC. His performance career as a soloist was short lived, however; in 1890, he became director of a chamber orchestra touring the east coast.
Split into simpler sentences: Cook had performed professionally as a student and made his debut in 1889 in Washington, DC. His performance career as a soloist was short lived, however. In 1890, he became director of a chamber orchestra touring the East Coast.