I'm writing a new piece with lots more solo lines than normal... and I'm not sure which instruments have portamento when they play. I usually never bother with it unless the instrument is stickin' out above the rest, all on its lonesome, and usually it's a violin so the portamento is a no-brainer. But I'm gettin' fancier these days, with horns and flutes and stuff.
With strings and trombone, it makes perfect sense because you slide around the notes while playing them... yet I think flutes exhibit portamento... and horns, maybe, too? And that doesn't make sense to me. They just have holes/valves/buttony thingies... if you cover them/press them, the note changes. Like a piano, sorta, in a weird way...? So how does portamento even function with winds/brass, if it's there at all?
To anybody with knowledge, I humbly request enlightenment!
All wind instruments are capable of "pitch bends" to a greater of lesser extent - often depending on the skill of the player. Sound production is a combination of air flow, embouchure tension, and resonant modes in the instrument itself. Pitch deviations can be as small as a subtle jaw vibrato where rhythmic and cyclical changes in jaw position affect airflow and embouchure tension to produce small variations in pitch, amplitude and brightness; or it can be as drastic as the kind of changes that produce the smooth and continuous clarinet gliss at the beginning of Gershwin's Rhapsody in Blue.