Vulcan lute

The Vulcan lute (sometimes referred to as Vulcan harp, Vulcan lyre, or Vulcan Lyrette) was a twelve-stringed instrument, played on the planet Vulcan, that was tuned on a diatonic scale and noted to be very soothing. 

Spock was proficient at playing the Vulcan lute and was known to play it often during his off-duty hours. 

Tuvok was also a proficient Vulcan lute player. He would often play his lute while reciting Falor's Journey to his youngest son. 

Melian, an Aldean musician also owned a Vulcan lute. .

One of Intendant Kira Nerys' Vulcan eunuchs played a Vulcan harp for her while a second eunuch gave her a massage. 

Background
The Vulcan lute seen in "Charlie X" was designed by Wah Chang.

The Vulcan lute has been described as a five-stringed instrument tuned in a diatonic scale in "Innocence", but is seen to have twelve strings. It is strongly suggested that the lute is instead tuned in a twelve-tone chromatic scale, since a seven-tone diatonic scale can fit in neither 5 nor 12 strings.

Lieutenant Uhura also demonstrated a proficiency for playing a lute somewhat different from Spock's, suggesting that she has an instrument of her own and was presumably taught by Spock,. She is the only non-Vulcan shown doing so.

In a deleted scene from, Spock revealed that he took second place in the All-Vulcan Music Competition, and that his father had taken first place.

The description of the Vulcan Lyrette from the original Star Fleet Technical Manual reads that this is "An unusually harmonious and melodic accompaniment or solo instrument, whose origin is lost in Vulcan antiquity. It combines the tonal qualities of a harp, lute, sitar, and to some extent, violin." They were usually made of Li'Pon and Sher Skah woods, with a Bahun'ahb inlay. The lowest pitch it can reach is 60 cps, and the highest is an astounding 3180 cps.