Emerging, like its fellow string instruments, from a long evolution (its immediate predecessor was the violone), the double bass gained its modern guise in the mid-18th century. Either plucked or bowed, it adds a deep resonance to the orchestral string section—something exploited powerfully by composers like Wagner, Bruckner, Mahler, and Richard Strauss. But it has a varied solo repertoire with an often charming side, as demonstrated in Schubert’s delicious Trout Quintet.