Vocaloid is a voice synthesizer software originally developed by Yamaha Corporation, which allows users to create songs by inputting melodies and lyrics. The software features various 'Vocaloids,' each with distinct voices, personalities, and appearances, leading to a vibrant virtual idol culture. Popular Vocaloids like Hatsune Miku have become cultural icons, inspiring concerts, merchandise, and even anime adaptations. The software first gained popularity in the mid-2000s and continues to have a significant impact on music production and fan communities worldwide.