In music, sampling is the act of taking a portion, or sample, of one sound recording and reusing it as an instrument or a sound recording in a different song or piece. Sampling was originally developed by experimental musicians working with musique concrete and electroacoustic music, who physically manipulated tape loops or vinyl records on a phonograph. By the late 1960s, the use of tape loop sampling influenced the development of minimalist music and the production of psychedelic rock and jazz fusion. Hip hop music was the first popular music genre based on the art of sampling - being born from 1970s DJs who experimented with manipulating vinyl on two turntables and an audio mixer.
Musical instruments
Whereas loops are usually a phrase played on a musical instrument, this type of sample is usually a single note. Music workstations and samplers use samples of musical instruments as the basis of their own sounds, and are capable of playing a sample back at any pitch. Many modern synthesizers and drum machines also use samples as the basis of their sounds. (See sample-based synthesis for more information.) Most such samples are created in professional recording studios using world-class instruments played by accomplished musicians. These are usually developed by the manufacturer of the instrument or by a subcontractor who specializes in creating such samples. There are businesses and individuals who create libraries of samples of musical instruments. Of course, a sampler allows anyone to create such samples. Possibly the earliest equipment used to sample recorded instrument sounds are the Chamberlin, which was developed in the 1940s, and its better-known cousin, the Mellotron, marketed in England in the 1960s. Both are tape replay keyboards, in which each key pressed triggers a prerecorded tape recording of a single note.  Musicians can reproduce the same samples of break beats like the "Amen" break which was composed, produced and mastered by The Winstons in 1960s. Producers in the early 1990s have used the whole 5.66 second sample, but music workstations like the Korg Electribe Series (EM-1, ES-1; EMX-1 and the ESX-1) have used the "Amen" kick, hi hat and snare in their sound wave libraries for free use. Sampler production companies have managed to use these samples for pitch, attack and decay and DSP effects to each drum sound. These features allow producers to manipulate samples to match other parts of the composition. Most sample sets consist of multiple samples at different pitches. These are combined into keymaps, that associate each sample with a particular pitch or pitch range. Often, these sample maps may have different layers as well, so that different velocities can trigger a different sample.  Samples used in musical instruments sometimes have a looped component. An instrument with indefinite sustain, such as a pipe organ, does not need to be represented by a very long sample because the sustained portion of the timbre is looped. The sampler (or other sample playback instrument) plays the attack and decay portion of the sample followed by the looped sustain portion for as long as the note is held, then plays the release portion of the sample.

Q: What were some musical instruments used
A: Music workstations and samplers use samples of musical instruments as the basis of their own sounds, and are capable of playing a sample back at any pitch.

Q: What other things did they use
A: Many modern synthesizers and drum machines also use samples as the basis of their sounds. (
Who used this
These features allow producers to manipulate samples to match other parts of the composition.
These features allow producers to manipulate samples to match other parts of the composition.