musical keyboard, menus, and buttons. These controllers enable the user to select different instrument sounds (e.g., piano, guitar, strings, drum kit), digital effects (reverb, echo, chorus or sustain), and other features (e.g., transposition, accompaniments, sequencer, recording, external media, etc.). The user interface system usually includes an LCD screen that gives the user information about the synthesized sound they have selected like tempo, or effects that are activated (e.g., reverb) and other features. Computerized musical arranger: A software program which produces rhythms and chords by the means of computerized commands, typically MIDI. Electronic hardware can also do this. Most computerized arrangers can play a selection of rhythms (e.g., rock, pop, jazz). Sound generator: A digital sound module, typically contained within an integrated Read-only memory (ROM), which is capable of accepting MIDI commands and producing electronic sounds. Electronic keyboards usually incorporate sample-based synthesis, but more advanced keyboards might sometimes feature physical modeling synthesis. Amplifier and speakers: an internal audio power amplifier, typically ranging from 5 to 20 watts, connected to the sound generator chip. The amplifier is then connected to small, low-powered speakers that reproduce the synthesized sounds so that the listener can hear them. Less expensive instruments may have a single mono speaker. Most models usually have two speakers producing stereo sound, often with tweeters for more advanced models. Power supply: Keyboards may or may not have an internal power supply system built to the main circuit board, but most modern keyboards are often equipped with an included AC adapter. MIDI terminals: Most keyboards usually incorporate 5-pin MIDI connections for data communication, typically so the keyboard can be connected with either a computer or another electronic musical instrument, such as a synthesizer, a drum machine or a sound module, allowing it to be used as a MIDI controller. Not all keyboards have conventional MIDI terminals and connector. The least expensive models may have no MIDI connections. Post-2000s keyboards may have a USB instead, which serve as both input and output in a single connection. since the 2010s, conventional MIDI in/out terminals are only available in professional-grade keyboards, stage pianos and high-end synthesizers, while low-cost home keyboards, digital pianos, and budget synthesizers use USB as the only connection available. Flash memory: Some electronic keyboards have a small amount of onboard memory for storing MIDI data and/or recorded songs. External storage device: Usually available on professional-grade keyboards and synthesizers, this allows the user