On April 12, Palm Beach Symphony will conclude its 2018-19 Masterworks Concert Series with a program entitled “Precious Gems” at the Kravis Center in West Palm Beach. The concert will include Mozart’s Piano Concerto No. 12 and Bruckner’s Symphony No. 7, with guest pianist Leon Fleisher joining the symphony for the Mozart piece. Fleisher took up the piano at age 4 and debuted at Carnegie Hall, playing with the New York Philharmonic, when he was only 16 years old. His…