I frequently hear mention of "performances" included in sample libraries. So quality sample libraries contain samples of each note of the scale for the range of an instrument, say clarinet, done with a number of different recorded velocities and articulations. A performance, I understand is more than one note, say a scale, recorded for that instrument, so that one can incorportate a more realistic scale or similar figure into one's music.
What I don't understand are the limitations to these performances.
- if a scale is recorded in C major, from middle C to the C an octave up, how does one:
a) alter the speed of this scale?
b) modulate this scale a minor 6th up for the key of A flat major?
c) keep the performance scale where it is at, but flatten the 7th because you are now in F major and want the b to be a b flat?
d) extend the scale that it starts on middle c and ends on the E a 10th above middle C?
Can these things be done, or are the performances greatly limited to the actual notes recorded so that one would have to work their piece to accomadate the performances?
In general the performances are used as an effect, rather than as musical phrases. Tremolo, slides, trills, falls, doits. stabs, glisses and really fast runs fall into this category. Regarding fast runs, they can be used as embellishments rather than, say, 64th note scales. There are also effects patches where the instrument is used to make some bizzare noises. These are generally tempo independent.
It is possible to use performances in an ACID-like context as well. Then you can change the tempo, if needed. Sounds like a lot of work to me. Kontakt has a Time Machine feature. I haven't used it, but it can be used to time stretch the performance samples to meet a desired tempo. According to King Idiot, Time Machine is really helpful when working in jazz and big band genres, since they really demand stylized performances. It's less needed in classical, where things are generally played pretty straight.