@sndyll welcome to Vocalodon!
Here is a Mastodon server for vocal-synthesizers' likers.
We use Local Timeline(LTL) like chatroom.
Default settings of toot is "post to LTL", so you can join to LTL without option changes.
If you want vocal-synthesizer, we recommend Kaai Yuki, an elementary school girl VOCALOID known "kawaii". 
@sndyll Welcome to Vocalodon, where people who like Vocaloid meet and chat in LTL, local timeline ( https://vocalodon.net/web/timelines/public/local Login required), so please take a look.💪(°∀°💪)
Japanese is the most common language, but English is also acceptable.
You can find us from the official app by clicking on the "Search" icon and then "Community".