The term "64th" refers to the ordinal number that comes after the 63rd and before the 65th. It is commonly used to indicate the position of an item in a sequence, such as in a race, a list, or a ranking. For example, a person finishing in 64th place in a marathon would be the 64th runner to cross the finish line. In music, "64th" can also refer to a note duration. A 64th note is a very short note that lasts for 1/64 of the duration of a whole note. It is often used in fast-paced music to create intricate rhythms and melodies.