- Vibrato makes the sound source appear to be a group of instruments playing the same part instead of a single instrument.
That is chorus. - Vibrato is the effect of modulating the copies of a sound source.
That is flange, phaser, and chorus. - Vibrato is the effect of modulating the frequency of a sound source.
Good job! - Vibrato is the effect of modulating the amplitude of a sound source.
That is tremolo.