What is that symbol in music that looks like an S on its side??

It is called Dal Segno or D.S.

Here is a link to explain how it`s used in a piece:
http://www.music-mind.com/Music/mpage6.HTM

Another symbol that looks like an S that sits between two notes is an Appogiatura.

For example if you had a B to a C with an appogiatura symbol in between you may play
B,A,B,C,B,,C rather just B and C or some other pattern depending on the style of music.

Piko, I don`t how I forgot THAT one The first thing that came up in my mind was "D.S. al coda".

I just happen to have been working on a lot of them lately. Really wish they were written out.

It all depends on which way the turn is flowing. If the turn dips and then peaks - you would play c,b,c,d,c

But if the turn peaks then dips you would play c,d,c,b,c

-Dennis (sarasotahair@yahoo.com)

Re: "Another symbol that looks like an S that sits between two notes is an Appogiatura."

Not to be confused with the non-harmonic tone called an appogiatura, which resolves stepwise, usually descending, after a leap, usually upward.

whats the diffirence between the 2 appogiaturas?

i only know the qiuck note used between 2 notes that usually resolves downwards. it looks like a little note.

are you talking about a grace note? a little note with a slash through the flag and stem?

-Dennis (sarasotahair@yahoo.com)

Re: "whats the diffirence between the 2 appogiaturas?"

The one is a kind of grace note, the other is a theoretical classification. When I hear the term "appogiatura", I automatically think of the latter, which is a more common usage.