1. Ukulele: A small, four-stringed instrument that is similar to a guitar but typically smaller in size.
2. Upright Bass: Also known as a double bass or contrabass, it is a large string instrument that is played standing up.
3. Udu: A percussion instrument that originates from Nigeria, it is a clay pot with a single hole in the bottom that is played by striking the opening with hands.
4. Unidentified Sound Object (USO): This term is sometimes used to describe experimental or unconventional musical instruments or sound-generating devices.
5. Uilleann Pipes: A traditional Irish bagpipe that is played while sitting down, with the pipes held on one arm and played using the other arm and fingers.
6. Umkulunkulu: A traditional stringed instrument from South Africa, it consists of a single string supported by a bow and played using a stick or quill.