While making music out of recorded speech samples was not a new idea in Steve Reich’s music, the Kronos Quartet’s release of Different Trains in 1989 gripped listeners with unprecedented potency. The work’s subject matter partly explains its impact—the voice recordings Reich uses recall both train journeys across America made in his childhood, and those made by Jewish prisoners to the death camps of the Holocaust. Howling train whistles haunt the textured soundscape woven by four string quartets (all played by Kronos), as the excitement of boyhood discovery morphs into unimaginable horror. David Harrington, founder and first violin of Kronos Quartet, recalls the complex recording process. “Different Trains was the first piece we played where we had to go into a studio and record it before we knew what it was really like,” he tells Apple Music Classical. “The recording came before a live performance.” The 1988 sessions took a total of nine days, as each quartet part was laid down by Kronos. “These days, you could do it all in a day,” says Harrington, “but sometimes perfection is not what you’re after. What you want is the struggle.” Steve Reich was present in the studio, hearing Different Trains for the first time with live instruments. Harrington remembers the discussion about whether Kronos players should employ vibrato: “I said to Steve, ‘If there’s ever a place in all of music where I think it would be good, it’s in the third movement where the woman says, “And the war is over.”’ If you’re going to add vibrato, that’s a great place to vibrate.” This iconic recording also features a luminous rendition of Reich’s Electric Counterpoint performed by guitarist Pat Metheny, the work’s dedicatee. It’s a feat of sonic sleight of hand as the soloist performs alongside their own pre-recorded track, to huge rhythmic and melodic effect.