The term tremolo refers to two quite distinct techniques. Bowed tremolo involves using the bow to repeat notes at a fast speed whereas fingered tremolo involves using the fingers to alternate rapidly between two notes. In both techniques the tremolo can either be measured (a specific note value such as semiquavers) or unmeasured (the notes are played as fast as possible). Depending on the speed, type and volume of a tremolo, the effect can add rhythmic energy or a non-rhythmic shimmer to the texture.
Bowed tremolo (unmeasured)
In the Schubert quartet below the use fast unmeasured tremolo as fast as possible with crescendi adds dramatic excitement, whereas in the following Grieg example the tremolo supplies an icy cold shimmer (enhanced by sul ponticello bowing – see later in handout) to a ghostly reprise of the theme from the beginning of the quartet. You can hear on the recording the much more energetic reprise that closes the movement.
Schubert Quartet 15 (D 887), second movement
Grieg String Quartet op. 27, first movement
Bowed tremolo (measured)
Measured tremolo creates a more rhythmic effect. In this Dvorak excerpt, the second violin and viola chug along playing two semiquavers per quaver, creating gentle rhythmic momentum under the calm violin melody:
Dvorak String Quartet Op. 34 in D minor (No. 9), first movement
Fingered tremolo (unmeasured)
Fingered unmeasured tremolo alternates rapidly between two notes, creating a slightly richer texture due to the impression of, in the example below, four notes playing almost simultaneously. In this Janacek extract, the tremolo is forte and quite vigorous but it works equally well when used more quietly. Fingered tremolo can also be measured.
Janacek, Intimate Letters, first movement