When cellist Joshua Koestenbaum was twelve years old, he wrote to legendary cellist Pablo Casals and received a letter in response. This March, Koestenbaum, now a member of the Saint Paul Chamber Orchestra, traveled with his colleagues to Puerto Rico to perform in the Casals Festival, founded by his childhood hero in 1957. While there, the musicians performed a program of Beethoven, Bruckner, Mozart, and Widmann. Former SPCO artistic partner Christian Zacharias conducted and was piano soloist in Mozart’s Piano Concerto No. 27, and SPCO musicians Ruggero Allifranchini (violin) and Hyobi Sim (viola) were featured in Jörg Widmann’s Aria for String Orchestra. Beyond music, there was a philanthropic aspect to the trip. Puerto Rico was hard hit by Hurricane Maria in 2017, and the orchestra encouraged friends and audiences back home to contribute to ongoing recovery efforts on the island.