Karaoke Kids

A basic karaoke machine consists of a microphone, a means of altering the pitch of the recorded music, and an audio output. Some low-end machines attempt to provide vocal suppression so that one can feed regular songs into the machine and suppress the voice of the original singer, however this is rarely effective (see below). Most common machines are audio mixers with microphone input built-in with CD+G, Video CD, Laser Disc, or DVD players. CD+G players use a special track called subcode to encode the lyrics and pictures displayed on the screen, while the other formats natively display both audio and video.
Most karaoke machines have technology that electronically changes the pitch of the music so that amateur singers can sing along to any music source by choosing a key that is appropriate for their vocal range, while maintaining the original tempo of the song. (There were some very old systems that used cassettes, and these changed the pitch by altering playback speed, but none are still on the market, and their commercial use is virtually nonexistent.)