The String Quartet No. 2 is a string quartet in D major written by Alexander Borodin in 1881. It was dedicated to his wife Ekaterina Protopova. Some scholars, such as Borodin's biographer Serge Dianin, suggest that the quartet was a 20th anniversary gift and that it has a program evoking the couple's first meeting in Heidelberg. Of its four movements, the third movement "Notturno" is …