The discussion centers on the movement of a guitar string at relativistic speeds, exploring whether this can be understood without delving into String Theory. The original poster seeks guidance on classical relativistic strings, expressing concern about the complexity of String Theory and its requirements. Participants clarify that while any object, including a guitar, can move at relativistic speeds, the concept of an unbreakable string is problematic due to implications of infinite speed of sound. They suggest looking into relativistic continuum mechanics and provide resources for further study, emphasizing that the string's behavior can be modeled without engaging with String Theory. The conversation highlights the distinction between mechanical relativistic strings and those in String Theory, ultimately guiding the poster toward accessible resources.