Murphy disbanded the outfit in 2011 shortly after the release of its third album, This is Happening, and now, less than five years later, he's hitting the road and the studio again with his former collaborators.
Responding to online criticism about the comeback, Murphy issued a letter on the band's website, calling the reunion "the bus full of substitute teachers back from their coffee break with new music and the same weird gear".
He revealed he took his new music to his LCD Soundsystem bandmates Pat Mahoney and Nancy Whang last year (15), and the trio decided the tracks should feature on a new group album.
Murphy fears fans who bought tickets for the final LCD show at New York's Madison Square Garden will feel cheated by news of the reunion, and ahead of their outrage, he writes: "If you cared a lot about our band, and you put a lot of yourself into that moment (or anything about us you chose), and you feel betrayed now, then I completely understand that.
"It's your right to define what you love about a band, and it's your right to decry their actions and words as you see fit, because it's you, frankly, who have done much of the work to sustain that relationship, not the band."
But Murphy assures everyone the group's new music and shows will be "better than anything we've done before", adding, "It won't have the help of being the first time, and we have to play better than we've ever played, frankly. Every show has to be better than the best show we've played before for anyone to even say, 'Well, that was good. I mean, not as good as they used to be. But, you know. It was good'."