Emvoice

Emvoice One is a vocal synthesizer plugin: you type lyrics and draw notes and it sings them, with controls for vibrato, glides and pronunciation. It's cloud-based, rendering from thousands of recorded samples, so it needs an internet connection. It's popular with songwriters and producers for demos and topline sketches because it sounds natural with little tweaking. The plugin is free; you buy the voices you want, and unlicensed voices are limited to an eight-note range.