A raft zither is a group of single-cord tube zithers, connected together to form a "raft". Tube zithers use a tube as a platform to hold a string (either tied onto the tube or cut out of the tube itself), raised with bridges. The flat surface of the raft is the base for the strings, and the multiple instruments form a single instrument with many notes. Each tube zither in the raft zither has a different note, and the idiochord instruments become a single instrument. The raft zither is also related to the board zither, which uses a board as the base for its many strings.