Set Flex Pitch Vibrato Tool
Set the Flex Pitch tool to Vibrato. Editing of sound recordings is completely out of my experience. I read about it. I hear about it. I have only briefly touched on the topic and how it is accomplished.
I almost exclusively use Flex Pitch to analyze audio in order to create a MIDI region for doubling or replacement. I am beginning to find places where a subtle change to a note can improve a work quite nicely. Hard to do with a stereo recording, but possible. Far easier to do with multi-track recordings.
Bring on the pitchy bass and tenor!
Edit pitch using Flex Pitch in Logic Pro — Apple Support
When working in the Audio Track Editor, the Vibrato tool allows you to edit the vibrato of a note without having to drag the hotspot.