In a deleted scene from “Elaan of Troyius”, Uhura suggested to Captain Kirk that “music hath charms to soothe the savage beast”, and thus they entered to find Spock playing a mating song on the Vulcan lyre. Uhura was deeply impressed with Spock’s musical abilities, and asked if he could teach her how to play the lyre. Spock approved, yet wondered whether a non-Vulcan could ever master the skill.
In a 2008 interview, Nichelle Nichols said “I created a relationship between Uhura and Spock as being her mentor and the person she looked up to. Uhura was the only one who could play the Vulcan lyre and the only one who had the audacity to sing a song teasing Spock.
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