In music, a glissando (Italian: [ɡlisˈsando]; plural: glissandi, abbreviated gliss.) is a glide from one pitch to another ( ). It is an Italianized musical term derived from the French glisser, "to glide". In some contexts, it is equivalent to portamento, which is a continuous, seamless glide between notes. In other contexts, it refers to discrete, stepped glides across notes, such as on a piano. Some terms that are similar or equivalent in some contexts are slide, sweep bend, smear, rip (for a loud, violent glissando to the beginning of a note),[1] lip (in jazz terminology, when executed by changing one's embouchure on a wind instrument),[2] plop, or falling hail (a glissando on a harp using the back of the fingernails).[3] On wind instruments, a scoop is a glissando ascending to the onset of a note achieved entirely with the embouchure, except on instruments that have a slide (such as a trombone).[4]
falling hail: gliding in the center of the strings with the back of the fingernails. (C. Salzedo)