Violin
Vibrato trill

A vibrato-like motion can sometimes be used to create a fast trill effect. To execute this effect, the finger above the finger stopping the note is placed very slightly off the string (firmly pressed against the finger stopping the string) and a vibrato motion is implemented. The second finger will lightly touch the string above the lower finger with each oscillation, causing the pitch to oscillate in a fashion that sounds like a mix between wide vibrato and a very fast trill. This gives a less defined transition between the higher and lower note, and is usually implemented by interpretative choice. This trill technique only works well for semi-tonal trills or trills in high positions (where the distance between notes is lessened), as it requires the trilling finger and the finger below it to be touching, limiting the distance that can be trilled. In very high positions, where the trilled distance is less than the width of the finger, a vibrato trill may be the only option for trill effects.
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