Expression & tempo
Portamento
Portamento is an audible slide between two pitches, produced on a string instrument by shifting while the bow keeps the string sounding.
Every shift contains a potential portamento; the choice is whether to hide it or shape it. Hiding it means lightening the bow during the travel so the slide is inaudible. Shaping it means keeping the bow engaged and controlling the speed of the slide, which is a deliberate expressive device in romantic repertoire and in early twentieth-century performance style.
It is distinct from glissando, which slides continuously through every pitch as a special effect and is notated with a line between the notes. Portamento is usually unmarked and is a matter of interpretation.
Related terms
Every term in this glossary is taught in context somewhere in Arco's curricula, on the staff, on the keyboard, and on your own fingerboard at the same time.