The great majority of artists spend their formative years (if not their entire careers) working to shake off the gravitational pull of their predecessors, and the many masters and masterpieces that came before them-what the literary critic Harold Bloom called "the anxiety of influence." For musicians, in particular, this tendency is especially pronounced, for reasons having to do with the nature of their craft and materials. Unlike the contemporary novelist or filmmaker, say, there is presumably a finite number of choices remaining to the artist making music in the 21st century that have not yet been exhaustively mined after 500 years of popular and semi-popular song. It is for this reason that, when we are asked to describe what a piece of music sounds like, we inevitably talk not about the thing itself, but resort to the trope of metaphor or analogy-"a little Brian Wilson, a little Pink Floyd, a little bit of Kraftwerk." Rare indeed is the artist who outgrows their early influences, and instead become one of the markers by which other groups are measured. Almost alone among bands of the last two decades, Tortoise is a group that resists easy metaphors and analogies, who can be described as sounding like only themselves and no one else. Twenty years after its founding, the band's signature and singularly inimitable sound-a fluid intersection of dub, dance, jazz, techno, rock, and classical minimalism, with no part overwhelming or dominating the whole-remains an American and international original. Even more unusually, they seem to have arrived at their sound with almost no apprenticeship to speak of; to judge from their early singles and albums alone, they seem to have come into being with their musical identity and DNA fully formed, like Athena from the forehead of Zeus. Further, while the group has spawned countless imitators, heirs, and followers-sincere, flattering, and otherwise-Tortoise remains unique in the world of contemporary music for their boundless intellectual curiosity, their unmistakable compositional voice, and their synthesis of seemingly contradictory sound worlds far from their doorstep.