The most bare-bone karaoke machines have an audio input, a pitch alternation switch and an audio output. Some advanced machines provide vocal suppression so that one can feed regular songs into the machine to filter out or greatly suppress the voice of the original singer.
Most common karaoke machines are audio mixers with microphone input built-in with CD-G, Video CD, Laser Disc, or DVD players which play with special media that encode the original song in one audio track and music only in another track. The video media also enable the display of the lyrics graphically on screen in sync with the music.
In some countries, karaoke with video lyrics display capablities is also called KTV. Karaoke machines may involve technology that electronically changes the pitch of music so that amateur singers can sing along to any music source by choosing a key that is appropriate for individual's vocal range. Sing-along karaoke machines that lack the pitch alternating feature are seldom referred as Karaoke.