Crescendo/Diminuendo Dynamic Markings

This is a simplified version of something I saw in a John Williams score:

I am thinking that the "sf" means that the note dynamic moves up to f and then back down again. There is no dynamic marking after the diminuendo, should there be?

What does the little hairpin under the note itself mean? This is what's confusing me.

And what does the "s" in "sf" actually mean/translate as?

Thanks.

the "little hairpin" is an accent mark.

the "sf" means "sforzando" = forced. it's a type of accent, similar to a fp.

it can also be written "sfz". it means sort of to accent the note and get softer.

the ending dynamic will be the same as the starting dynamic, I presume, since I can't see the score.

so this means the music gets louder and there's an accent with a sudden getting softer, then further diminishing over the length of the note.

I suspect that what you saw was over a longer value of note? For a single quarter note it seems rather fussy as notation.

Ah, thanks, I can hear the accent clearly now.

It is actually only for a length of 3 quavers, although it is quite a slow piece. It's this one here from Harry Potter:

The note I drew is on the 10th beat of the piece.

As QcC said, sf is an accent and thus not strictly a dynamic marking (even though practically speaking it will be -performed- as a variation in dynamics). Therefore it is rather independant of the dynamics surrounding it: A sf or sfz can stand in a piano passage as much as in a fortissimo passage and generally doesn't change the loudness -after- the note it stands under, but just designates an emphasis on this single note. So if the passage before this is pianissimo, after this it would be pianissimo again, even without noting anything else.

It is of course often used rather inconsistently, and depending on the composer it is either a relative or absolute value: I.e. either it means the same loudness independant of whether it appears in a pianissimo or fortissimo passage, OR it is an accent that is relative to the loudness surrounding it, i.e. quieter in a pp passage, louder in a ff passage. Generally I would assume the latter.

And sometimes (rarely though) it's even used to mean "subito forte", which is of course something entirely different, and in this case really a dynamic marking. But in the general case, assume that after that sign there is again the same loudness as before it.

I don't get why he puts both the accent and the sfz. Usually, I would just use the accent; in this case I would use the sf just because it looks better to have some indication between the hairpins. But both at once seems superfluous.

As a side note (haha) on Williams notation, I've noticed that he really likes martelato (third articulation):

I don't think I've ever seen that in a classical or romantic score (whereas the simple accent, #4, is like an old friend :)), but I'm a string player, it may be more of a wind/brass articulation.

I don't get why he puts both the accent and the sfz. Usually, I would just use the accent

As a side note (haha) on Williams notation, I've noticed that he really likes martelato (third articulation):

I don't think I've ever seen that in a classical or romantic score (whereas the simple accent, #4, is like an old friend :)), but I'm a string player, it may be more of a wind/brass articulation.

Absolutely....

Accent #4 (>) is hit hard, but sf or sfz are hit hard. The difference between a Count Basie accent, and a Thad Jones accent. ;)

Accents aren't necessarily louder, they are stressed. This could mean a down-bow, a degree of pontecello, merely vibrato or any form of differentiating the accented notes from the others often in the form of timbre changes as well as the obvious dynamic changes.