Portamento

Also known as ‘glissando’ or ‘glide’. If you play one note after another the pitch changes gradually (at a predetermined rate) from the first pitch to the second. A familiar feature on early monophonic synthesizers, portamento can often be found on polyphonic instruments, where you can generally decide whether you want each glide to change pitch at the same rate, or have each glide take the same time to arrive at the final pitch. The latter is useful for gliding relatively harmoniously between chords, as all the notes in the final chord ‘arrive’ at their new pitches at the same time.