Polychord: (Also called a bi-chord) are two chords played at the same time. An example of this is when a pianist plays one chord with the right hand and concurrently, another chord with the left hand.
Delay: For audio recording and guitar FX nomenclature, delay is a type of buffering that delays the output of the signal by an amount of time. The signal is stored in a buffer (originally on tape) in the effects equipment and played back after a period, generally selected by the user. A delay effect can repeat multiple times, usually—though not always—with each repeat progressively quieter.
Echo: In audio FX terminology, echo is nearly synonymous with delay. However, echo FX generally “color” the repeated sounds using a low, high, or band pass filter. This better simulates the sound of what the layperson would call an echo.
Reverb: In audio FX terminology, reverb is similar to, but distinct from delay and echo. It is similar in that it repeats the captured audio. However, reverb is generally attempting to simulate the bouncing of sound off of many surfaces. As such, rather than controlling the number of repeats, the user tends to control the “amount” of reverb. That is, the number of repeats are more randomized and played back much closer to the time of the original signal. Similar to echo, reverb pedals also tend to color the sound of the reverberations.
Midas preamp: Midas is a designer and manufacturer of audio equipment. The Midas preamp is commonly used in Front of House (FoH) equipment, monitor consoles, and mixers. Their A/D convertors and sampling rate reportedly has better sound quality than many other brands of preammps.
Hi Z: Z is commonly used as a reference to impedance. A hi-Z input on an audio device is a high impedance input. An unamplified electronic guitar or bass needs to be plugged into a hi-z jack. Since the guitar cable is not balance the signal will be degraded if connected to a low-z jack.
RTA: Real Time Analyzer is used to read frequency response. In the case of music recording/mixing/playback it is used to adjust and equalize the sound for different applicatoins. In a live venue it allows for mixing the sound to compensate for room sound anomalies. For post process mixing it aids the person mixing/mastering by providing a visual display of the actual frequencies to augment what they are hearing.
Truss rod: Truss rods strengthen the necks of stringed instruments and help prevent unwanted bowing introduced by the tension of the strings and climate. They are commonly made of steel but there are some different composites used, such as graphite. There are single and dual truss rods. Both run the length of the neck under the finger board. The single truss rod usually runs in a curved channel that allows for more of a fulcrum when being tightened. The dual truss rod is installed in a straight channel since the rods “bow” in different directions and can warp or adjust the neck in either direction. Most truss rods are adjusted by turning an adjustment bolt. These are located at different places on different instruments.
Reprise: In music, a reprise is a repeated passage in music or a repeat of a section of music or an entire performance.