Note(s) that preceed the first strong metrical beat, usually the first beat of the measure.See also anacrusis.An electromagnetic device mounted under the strings of an electric guitar or electric bass that senses the frequency of the vibrations of the strings and converts them into electrical impulse for amplification or recording. This works on a simple principle of physics. A vibrating metal object (the electric guitar string) moving in a magnetic field creates an electronic signal that can be sensed by a wire coil. So the electromagnet of the pickup can sense the frequency of the vibrations of the strings and convert them into electrical signals that travel through a cable to the amplifier to increase and or alter the sound. (This same principal is the basis for electric motors, generators, phonograph needles, and accoustical speakers.) Pickups for electric guitars and electric basses were being developed in the 1920's. The early pickups were designed to amplify the natural sound of the acoustic instruments and used the bridge of the instrument to move the vibrations to the electromagnet, but the signal was often too weak to be effective. When engineers utilized a direct pickup system, in which the electromagnet received the string vibration from the strings themselves, the modern electric guitars became a reality. By 1961 the electric guitar was in it's full maturity and pickups were created in single-coil and double-coil, or humbucking designs. Gibson introduced "Humbucking" pickups into the Les Paul electric guitar, and was designed to eliminate unwanted hum from the magnetic coils. Humbucking pickups utilized two coils wrapped out of phase so as to cancel out the common mode hum introduced by previous designs.<br><br>1) A device on an electric guitar (or other instrument) that puts out an audio signal according to the string motion on the instrument. 2) A device that puts out an audio signal according to the vibration of something; this term means the same thing as a contact microphone.