Complex sentence: In 2007, the Symphony toured the Baltics (Finland, Estonia, Russia) with featured soloist piano prodigy Chloe Pang, who played Rhapsody in Blue by George Gershwin.
Split into simpler sentences: In 2007, the Symphony toured the Baltics, visiting the countries Finland, Estonia, and Russia. The featured soloist was piano prodigy Chloe Pang, who played Rhapsody in Blue by George Gershwin.