Question about technical terms for singing methods

[repoman]

I have more than one, but only one exact example now.

This woman does what I would call a vibrato with her voice, I think that it is the wrong term. Also, it seems like it may happen without even conscious effort which may mean it has a different term for it.

The one in the middle has the singing style:


Also, how far up and down from the note is she?

 

[PyramidHead]

It sounds like a very fast, shallow vibrato to me. Probably less than a quarter-tone in either direction.

 

[repoman]

So, I just listened to an a quartet piece with the same woman in it (pink shirt). Her short shallow vibrato totally changes the song compared to how it would sound with an average amount of vibrato or steady tone.



Sometimes it is pleasant, and other times a bit dissonant how the voices mesh given the vibrato. But it does make it interesting. Also noticed the vibrato increased a lot when hitting higher notes and more volume.

What would be an instrumental analogy of this? What would you call it when one instrument is vibrato against one or more steady toned instruments?

Ha, maybe I like the singer in the same way I like Theremins. I think that she should practice being able to shut off the vibrato when a song calls for it. She does have a very nice tone without it.