Anyone know what this is?

on wikipedia, I found out about these following sheet music items:

Demi-flat
Flat-and a half
Demi-sharp
Sharp and a half
Breve
Longa
multi-measure rest
Grand pause
trill
mordent
turn
Appoggiatura
Acciaccatura

Any body know what any of these are, My piano teacher said she has never heard of a demi-flat or a flat and a half.

Right, let's see if I'm still able to pass a music test

Demi-flat
Flat-and a half
Demi-sharp
Sharp and a half

Those are used mostly in microtonal music, and using them you can divide the interval between two notes in not only 1 step, but three. Like this: in our well known 12-tone equal temperament, between C and D you have the C# (or Db), making:
C - C# - D
With a quarter tone microtonal music, between C and D you have: C demi-sharp, C#, C#-and-a-half (or Db-and-a-half, Db, D demi-flat), making:
C - C demi-sharp - C# - D demi-flat - D


Breve

A breve is a note with double the value of a semibreve (that's what the "whole note" is called in italian and latin languages), so in an 8/4 bar a breve would fill the whole bar.

Longa

A longa is double the value of a breve, so in a 16/4 bar a longa would fill the whole bar

multi-measure rest

That one explains itself, doesn't it? It usually comes with a number over it, meaning: Pause for this many bars. So, if you are in an orchestra and you're playing timpani, but you'll only be playing at the very end of the piece, you may have this rest with a number like 130 over it, so you'll wait 130 bars before you play. Think about the trees, you don't want to print a bunch of sheets with only rests on it, do you?

Grand pause

This one I'm not sure, but I think in an orchestra when you reach this pause, you'll stop playing for an indefinite time, and you will wait for the conductor to signal you when to resume playing. I don't know if this pause is used on solo pieces, never seen one, but if I did I would treat it like a fermata.

Those below are ornaments:

trill

in a trill you alternate between the note printed and the note right above it rapidly, for as long as the duration of the printed note lasts. So if you have a whole note C with a trill, you'll play C D C D C D C D C D C D for the duration of a whole note.
(note: with some baroque composers, specially Bach, you'll start the trill with the upper note, not the printed note, so the above would become D C D C D C...)

mordent

There are two of these, the superior mordent and the inferior mordent:
On the superior mordent, you'll play the printed note, the note above it, then the root note again, all these of course, inside the duration of the printed note. So, for a quarter note superior mordent on C, you'll play: C D C in the duration of a quarter note.
(note: what I said about Bach applies to the mordent too, so this example would become D C D)

The inferior mordent is basically the same as the superior, except you'll play the root note, the note below it, then the root note again. So, for a inferior mordent on C, you'll play: C B C

By the way, so you can tell one from the other, the inferior mordent has a line cutting it vertically

turn

For turns (or gruppettos) there are three types:
If the gruppetto is over the printed note, you'll play the upper note, the printed note, the lower note, then the root note again (all, of course, inside the duration of the printed note)
So, for a C with a gruppetto over it: D C B C

If the gruppetto is ahead of the printed note, it's almost the same, except you'll start with the printed note, then play the notes I said above.
So, for a C with a gruppetto ahead: C D C B C

And there's a gruppetto with a vertical line cutting it, and that means you'll swap the upper and lower notes.
So, for a C with a gruppetto with a line, over the printed note: B C D C

Appoggiatura
Acciaccatura

The appoggiatura and the accacciatura are also known as "grace notes", and they look like tiny notes right before a regular note, and they're joined by a ligature.
With the appoggiatura, you'll play briefly the grace note, almost half of the duration of the printed note I guess, then the printed note (but both notes should fit inside the duration of the printed note).
And the accacciatura is even more brief, almost as if both notes are played together



Right, so I'm waiting for my score on the test

Wow, that was really explanitory, but a

Demi-flat
Flat-and a half
Demi-sharp
Sharp and a half are used in microtonal music ,right? What is microtonal music? and you can't play any those on a piano, can you?

I guess you can, if you retune the piano.

Hi there

The Grand Pause is also known as the Generalpause and this is indeed the same as a fermata. The performer or conductor holds the note (or the rest) for longer than the note value (usually one and a half times the value, but at the performer's discretion). It is usually notated G.P. and is more common in orchestral music than piano scores.

Hmm, I'm just guessing a demi-flat/sharp in brief are a half of a semi-tone? I think you can play them on a clarinet by half-pressing the register-key while playing the two semi-tones between this certain demi-flat/sharp is. But yeah, I've been wondering what these were for a while!