A mouth organ, also known as a harmonica, is a type of musical instrument that is played by using the mouth to blow and create sound. However, there are several other synonyms for the term that are used in different parts of the world. For example, in the United Kingdom, it is commonly referred to as a "harp", while in Ireland it may be called a "tin whistle". In the United States, the term "mouth harp" or simply "harmonica" is widely used. Additionally, in India, the instrument is often called a "mukhavina" or "shankha". No matter what it's called, the mouth organ remains a beloved instrument for musicians and music enthusiasts around the world.