How to find natural vibrato: a one-semitone pitch oscillation from the diaphragm, not the jaw. Train it across your vocal range.
Natural vibrato, shaped by breath and ease
Vibrato is a pitch oscillation of about one semitone around the main note. On any sustained note, adding vibrato makes the voice sound sweeter and deeper β and more interesting to listen to than a straight, pure tone. That is the target of this package: natural vibrato, not a wobble you add on top. It comes from a subtle pulsation of airflow together with a change in vocal cord tension. The airflow pulsation is produced by pushing from the diaphragm. That is why you do burst breathing exercises every day: diaphragm control is what drives the pulse. Vocal cord stretches relax the airway so the pitch can bend.

Natural vibrato should never come from jaw quivering. In these vocal exercises, hold the jaw steady. Pitch bending should only come from diaphragm pushes and vocal cord relaxation β not from jaw motion. If you already have vibrato when you sing, still do the training. The point is to confirm the vibrato is proper and efficient: diaphragm and cords, not the chin.

Weeks 1β2 β Bounce: get ready for the vibration. Destiny: get rid of jaw shaking for vibrato. Peripheral training: the origination of vibrato.
Weeks 3β4 β Note bending for one semitone. Bending in chest: push vocal-cord bending in chest register. Bending in head: the same bend in head register.
Weeks 5β6 β Let it out: release vibrato by diaphragm push and vocal cord relaxation. Tone variation: vibrato for different tone qualities. Practice until muscle memory holds. Mastery: that subtle pulsation of airflow together with a change of vocal cord tension.
Vibrato feels different in different registers β from heady high notes to chesty low notes. You have to practice it in all parts of your vocal range, not only on the one comfortable note where it already appears. Come in and work out every day. Muscle memory is built by that repetition.