reginaldStjohn
You can't really add vibrato like you can in VVocal. You can enhance or de-emphasize if but is none is there originally you can't create it or change its frequency etc. At least not to my knowledge.
See post #319. Even though the Sonitus Modulator is not within Melodyne, it provides the exact same functionality as V-Vocal's vibrato tool - imposes LFO-based frequency modulation. The only difference is you have much more flexibility than the V-Vocal vibrato tool because you can automate the vibrato for more expressiveness.