Musk, originally derived from the male musk deer, is a foundational ingredient in perfumery due to its unique scent and fixative properties. While its natural source had ethical and conservation implications, this led to the development of synthetic and plant-based musk alternatives in the 20th century. 

These synthetic musks, which range from aromatic to polycyclic types, mimic the scent and qualities of natural musk. Today, most musks used in perfumes are synthetic or plant-derived, and they remain essential in creating long-lasting, diverse fragrances.