What's a Vocal Synth?
"A vocal synthesizer is easily defined as 'an electronic instrument that generates and combines the basic elements of sound to produce simulated speech, typically used in computer systems." - TakeLessons
UTAU
UTAU is a Vocal Synthesizer created by Ameya/Ayame. The program was first released in 2008, functioning for only Japanese CV Voice Banks. But somewhere in the 2010s, with more updates, many users from around the world create recording lists to make their singer sing in other languages, like English, Korean, Spanish, Chinese, etc..
Deepvocal
Deepvocal is a Vocal Synthesizer created by Boxstar in 2019. The program started with only functioning Chinese (Mandarin). But somewhere around the 2020s, like UTAU, users started making voice banks for Japanese, English, amongst many other languages.
NIAOniao
NIAOniao is a Vocal Synthesizer created by dsound. The program started functioning for only Chinese voice banks. But, Virtual Singers like UTAUloid "Magone Mako" and "Dong Fang Zhi Zi" came out with Japanese voice banks for NIAOniao.
Diff-SVC
"Diff-SVC is an open-source Singing Voice Conversion project using the Diffusion model." - GitBook
Diff-SVC Tutorial by UTAUraptor
RVC
"RVC, short for Realistic Voice Cloning, is an advanced AI technology that excels in creating highly realistic AI voice models. It relies on the latest voice analysis technology to analyze any voice material and finally generates a voice model." - TopMediai