(covers information from several alternate timelines)
The following is a list of unnamed musical instruments.
Adam's guitar was a musical instrument used in the 23rd and 24th centuries.
Aldean musical instrument
The Aldean musical instrument was an advanced device controlled by thoughts. The player put his fingers on certain pads on the instrument and simply felt the notes in his head. If done correctly, the instrument would start to glow in different colors and produce a melody that was similar in mood to the player's feelings and thoughts.
Algolian musical instrument
The Bajoran cabasa was a small percussive musical instrument that played a role during Bajoran births.
For Bajoran women, it was important to be relaxed during birth, so the mother's relatives would play different instruments in a repeating rhythm to provide a relaxed atmosphere.
The Bajoran gong was a small percussive instrument that played a role during Bajoran births.
For Bajoran women, it was important to be relaxed during the birthing process, so the mother's relatives would play different instruments in a repeating rhythm to provide a relaxing atmosphere. During Kirayoshi O'Brien's birth, his father Miles O'Brien played the Bajoran gong; he had trouble keeping up the rhythm, however. (DS9: "The Begotten")
The Bajoran harp was a small, four-stringed ritual musical instrument that resembled a crescent moon with bells strung across it.
A Bajoran lute was a type of musical instrument that was very similar to the Vulcan lute.
Bajoran percussion instrument
The Bajoran percussion instrument was a mixture between a xylophone and a drum played with small hammers.
A Bajoran musician played one of these instruments, accompanied by a Bajoran lute and a Bajoran woodwind instrument during the Gratitude Festival aboard Deep Space 9 in 2371. Odo was especially fond of the sound of those instruments. (DS9: "Fascination")
The Bajoran rattle was a small percussive musical instrument that played a role during Bajoran births.
For Bajoran women, it was important to be relaxed during birth, so her relatives played different instruments in a repeating rhythm to provide a relaxed atmosphere.
The Betazoid chime was a small crystalline octagonal instrument that was struck with a little hammer.
On Betazed, it was customary to strike the chime during a meal to express gratitude for the food that is consumed. Homn struck the chime during a banquet aboard the USS Enterprise-D celebrating the upcoming marriage between Deanna Troi and Wyatt Miller in 2364, (TNG: "Haven") and again the next year, when Captain Jean-Luc Picard was having a private dinner with Lwaxana Troi. (TNG: "Manhunt")
Café des Artistes instrument
In a holographic recreation of the Café des Artistes in the year 2342, a musician played an instrument that consisted of a small rectangular box with several glass tubes. (TNG: "We'll Always Have Paris")
Enaran musical instrument
The player had to put their hand on a glowing semi-globe and focus the thoughts. Depending on what they felt, a different melody would emerge.
Jor Brel mastered this instrument and taught Captain Kathryn Janeway telepathically how to play it, the feeling was a little overwhelming for the Captain, though. Jora Mirell also composed music for this instrument. (VOY: "Remember")
Instrument in Quark's
Kriosian musical instrument
The Kriosian musical instrument was a large instrument from planet Krios that was similar in appearance to an Earth xylophone.
It was part of the wedding ceremony to play the instrument according to a certain discipline, called torze-qua. As Ambassador Briam was unable to attend the ceremony, Kamala taught Captain Jean-Luc Picard how to play the instrument. (TNG: "The Perfect Mate")
Mataline II piano
The Novans on Terra Nova created several musical instruments out of the skulls and bones of Diggers they gutted in their gutting room. In 2151, Malcolm Reed listened to music performed by several Novans in their underground tunnels and caves. (ENT: "Terra Nova")
The Taresian chime was a small crystalline octagonal instrument that was struck with a small hammer.
Varieties included a small piano-like instrument that can be easily transported and a larger stationary piano model. Joran Dax was a talented player of this musical instrument. (DS9: "Equilibrium", "Field of Fire")