Violas: Left Hand

The basic hand positions:
High positions:

Vibrato

Pitch undulation created by motion of the wrist and finger. Not normally notated, but if extra vibrato is required, indicate molto vib under note(s). Vibrato is inherent to a player's technique and each player executes variable amounts depending upon interpretative intentions. It is possible to execute vibrato on open strings, but this is not normally done unless specifically requested.
Vibrato:
Difficulties in using vibrato on high notes:
Db3 Eb4 E5 C6

Non Vibrato

No undulation in pitch. Notated: non vib. or senza vib. Must be specified. Players will sometimes add tiny amounts of vibrato even to passages marked non vib depending on musical interpretation.
Non vibrato:
Db3 Eb4 E5 C6

Glissando

A continuous slide in pitch. Consider rate of glide, start and end points.
Glissando:
Glissando across strings:

Db3-Eb3 Gb3-Bb3 Bb3-Eb4 A4-E5 E5-A4 A4-Eb4 Eb4-Bb3

Portamento

A slide from one pitch to another, usually stopping for moment either above or below the destination pitch. Essentially an expressive device which was very popular in the 19th and early 20th centuries, but has more recently fallen into disuse.
Portamento:

Trill

A rapid alteration between two pitches either a tone (major trill) or a semitone (minor trill) apart. This shows a minor trill followed by a major trill, indicated by accidentals over the note. If these are not given, players will choose trill type based on musical context. The wavy lines indicating duration of trill are also optional. In highly chromatic music, it is a good idea to specify the pitch onto which the trill is made in brackets after the note.
Minor trills
Eb3 Gb3 B4 Db6
Major trills
Eb3 Gb3 Eb6

Fingered Tremolo

A trill between two notes more than a tone apart. This is an unmeasured tremolo and lasts two beats. A measured tremolo is simply an alteration between the two notes in regular note values and is usually notated as such.