Tonight, the storied ensembles play at the Berlin Philharmonie, performing Ralph Vaughan Williams' Fantasia on a Theme by Thomas Tallis and Mahler's Sixth Symphony. On May 9, they perform the same program at the Vienna Konzerthaus.
The two orchestras have "have a long friendship and a long, sometimes difficult rivalry," Rattle told the BBC. After performing together, he added, "they will know each other better, will understand each other better, will love each other more than they already do, and maybe we will learn something from each other."
Rattle, the celebrated former music director of the City of Birmingham Orchestra, has led the Berlin Philharmonic since 2002. He turned 50 in January.