Question Regarding Brass and String Techniques

Hi,

I've always wondered what the technical terms are for the following techniques heard in strings and brass instruments.

The first technique is used in strings at the extreme of their ranges: extreme strings snippet: listen online

And the brass 'modulating pitch' technique: brass snippet: listen online

I would like to ask the following questions about both techniques: How do the performers achieve the effect? What is the technical term for the technique (if any)? and finally, How would I, as a composer, indicate to the performer to play these effects in terms of score markings (basically what do the performers see on the score that tell them to do the techniques)

Hope I explained myself ok.

Thanks alot

the string part is just a tremolo while doing a rising glissando in the high register.

the brass notes are either shakes or simply trills. it partially depends how you orchestrate it. you can get more or less the same effect by simply notating tight chord harmony with trills on all the notes.

Oh right so the strings are just very high notes?

Do you know how I would achieve the effects in Sibelius 5.