This is simply a synth playing a c note with the pitch automated. Typically used in modern electronic music to signify a build and create an euphoric feeling.
This is the first of a bunch of theremin improv loops i'm doing. If you don't know what a theremin is use google. This was played on an etherwave standard.
Sample made in sfxr with layered sawtooth waves in harmony and sliding highpass and lowpass filters, then used as a note in sfozando to create an uneasy melody.