A karaoke machine mixes a vocal signal corresponding to a live singing voice inputted through a microphone to a music signal reproduced from a musical source and representative of melody and accompaniment of a karaoke music piece. The mixed signals are sounded through a loudspeaker. A karaoke system reproduces music from popular songs and allows users to sing along into a microphone and mix their voices with the music. The basic and most common karaoke machines output the instrumental portion of a song with the lead vocal removed, and substitute in its place the voice of the karaoke user singing the vocal through a microphone. A karaoke system is provided with a mixing function for mixing and outputting a reproduced piece of music, that is, an accompaniment and a singer's voice input from a microphone. The karaoke user's voice and the music of the song are mixed and outputted, typically to an audience. To prompt the singers, the karaoke unit displays the lyrics to the song on a screen. The lyrics will often be highlighted or otherwise give cues to the singers as to when each word of the lyrics is to be sung. Graphic or video images may also be displayed along with the lyrics. The karaoke musical accompaniment generated by controlling a synthesizer by the MIDI data is inherently lower in quality and atmosphere as a music and a tone quality in comparison with the reproduced sound of the digital audio data of the musical accompaniment. In a karaoke machine, a karaoke amplifier is used to adjust parameters of microphone inputs, volume of music sounds and various sound effects according to setup positions of analog operation keys. Voltage values (analog amounts) in the karaoke amplifier corresponding to the setup positions of the analog operation keys are converted into digital values by an A/D (analog/digital) converter. According to the digital values, the karaoke amplifier adjusts a volume and a tone of vocal sounds and instrumental accompaniment sounds of a karaoke performance, and further controls various acoustic effects of the sounds such as an echo level. Generally, a karaoke amplifier is provided with a circuit which imparts an echo or reverb to the vocal sound signal input through the microphone, as means for enhancing the stage effect of the singing. In a karaoke apparatus, lyric words are displayed in matching with the performance of a song, and further, for enhancing an atmosphere or mood of the music, background pictures are reproduced and displayed simultaneously with the music performance as BGV. Karaoke machines display a background video for the karaoke music piece being played. Generally, the background video requires a huge volume of video data. The karaoke machine stores pictures of the background video of various genres, and selects a suitable picture of a desired genre to which a requested music piece belongs, in terms of an attribute such as a season that the requested music piece presents. The background video that supports or accompanies the karaoke playing has diverse properties such as location, atmosphere, character and so on. In the background video for one piece of karaoke music, scenes change one after another as the karaoke music piece progresses.

Karaoke apparatuses generally have various facilities to show up a karaoke performance. The facilities include a harmony voice generation to add a synthetic harmony voice to a karaoke singer's live voice. The harmony voice generation is performed by creating a harmony voice having a certain pitch difference such as 3rd or 5th degree relative to a melody line of the main live vocal while tracking the melody line. Some karaoke machine is installed with a sophisticated tone generator, i.e., a musical sound synthesizer which is generally adopted in an electronic musical instrument or a computer music box. While the tone generator is driven according to registered accompaniment information of the instrumental accompaniment, a display device is driven concurrently according to registered word information to visually indicate song words in the form of a sequence of characters in synchronization with the automatic instrumental accompaniment. Such type of karaoke machines can store karaoke data and background image data separately from each other such that one set of background image data can be shared by different karaoke entry songs. By this, the number of record disks storing the background image data can be reduced to simplify the overall construction of the karaoke machines. An important enhancement to the basic functionality of karaoke and attempt at making it more accessible to the novice is a feature called vocal partnering. This feature enables outputting the OMR when the karaoke user's voice drops below a certain volume level. Hearing the OMR can assist the karaoke user in getting back on track in the song. To enhance the entertainment value of karaoke, a typical karaoke apparatus also includes a performance evaluator which generates a score. A variety of karaoke apparatuses have a capability of scoring the singing skill of a singer. A singing voice of a singer is compared in volume and pitch with reference data of a vocal part included in karaoke music information. The singing skill of the singer is scored based on the degree of matching between the singing voice and the reference data in terms of volume and pitch. The performance evaluator employed in the existing karaoke apparatus normally contains pre-recorded scores in a read only memory (ROM) device. Upon the selection of a particular song, the performance evaluator is activated by the transmission of the accompanying music thereto. Thereafter, when the accompanying music is ended, the performance evaluator randomly selects any one of the pre-recorded scores and transmits the selected score to the display. In a karaoke machine, when a music piece is specified, performance data are read out from storing means in accordance with the specified music piece, and a performance of the music piece is reproduced based on the performance data. Generally, performance data used in a karaoke apparatus are produced by way of editing and processing. The performance data are once written on a recording medium by an apparatus called a sequencer, and then read out. The sequencer functions by conducting a change of the sound-producing timing indicated by the performance data on the performance data in one track, and a function of changing the volume.

There are various karaoke systems with audio-visual capabilities, such as: laser discs, video cassette recorders and CD graphics. There are also certain types of karaoke players without visual display capabilities, such as: audio cassette multiplex players. This type of the Karaoke apparatus is installed with a mixer which mixes a physical singing voice picked up by a microphone with the Karaoke accompaniment together with a reverberation effect or else, thereby enjoying an interesting song performance. The conventional karaoke apparatus is classified into either of a stand-alone type and a terminal type. The stand-alone type of the karaoke apparatus is most widely spread out in the commercial market. The stand-alone type is equipped with a closed data source for storing a complete set of numerous song data required for karaoke performance in a self-support basis. On the other hand, the terminal type of the karaoke apparatus is connectable to a central station through a communication line to receive song data therefrom. This type can eliminate a closed data source which contribute to simplification of the karaoke apparatus. In recent years, karaoke systems have become very popular, and there are an increasing number of demands among users for a larger number of song titles as the number of users of karaoke systems increase. Karaoke network systems that are capable of presenting commercial messages have become popular. A typical karaoke network system includes a host computer installed in a central station and, typically, a plurality of karaoke stations, each of which is installed in a business establishment, such as, for example, a bar, a club and the like. Each of the karaoke stations is connected to the host computer via a communication line that supplies karaoke song performance data from the host computer to the karaoke station. A karaoke network system having the central station and the local karaoke terminals is classified into either a two-way communication type or a one-way broadcast type. In the communication type of the karaoke network system, the karaoke terminal transmits a request command to the central station through a telephone line, while the central station responds to the request command to thereby instantly transmit back requested song data to the requesting karaoke terminal. In the broadcast type of the karaoke network system, the central station successively broadcasts numerous pieces of song data in endless manner to all members of the karaoke terminals through a communication network composed of a cable line or a wireless line, while each karaoke terminal can pick up a desired one of the broadcasted song data pieces. The karaoke terminal are free from a communication cost for two-way exchange of a request command and a corresponding song data. In a typical karaoke network system, a karaoke station that is installed at an individual business establishment has a ROM (read only memory) that stores a system program and an internal CPU (central processing unit) that executes the system program stored in the ROM to carry out various control operations. In an online karaoke system, a center station holding a karaoke database supplies karaoke data through a public network or the like to karaoke terminals installed in a karaoke bar or the like or to a sub host station upon request from the karaoke terminals or sub host station.

A karaoke system of communication type is called a communication karaoke in which karaoke data is distributed through a communication line to a karaoke terminal having a sound source for karaoke performance. The communication karaoke system is a large-scale computer network including a host computer and a number of remote terminal apparatuses arranged nationwide communicating with the host computer via a communication network or a multimedia system handling various digital audio and image information, including moving pictures. In most communication type karaoke machines, data compressing and communicating techniques with a view to minimizing a total data quantity of music piece data per music piece are employed to achieve a minimized communicating time and minimized necessary storage space. The communication karaoke machines stores song data for performing karaoke songs separately from background image data to be displayed on the monitor as the background image together with lyric words of the karaoke song. A background image suitable for a requested karaoke song is selected for reproduction. In a communication karaoke system, karaoke data including music control data, word control data, and picture data is handled as one or more files. The distributed karaoke data is temporarily stored in a recording medium such as a hard disk. When a karaoke song is specified, the karaoke data corresponding to the specified song is all loaded into a memory before karaoke performance of the song starts. In a karaoke system via communication, a center, storing data of a plurality of songs, transmits the data of songs to a terminal connected with the center via a telecommunication line. In a communication karaoke system, the terminal device includes a memory device for storing the song data supplied from a supplier. When a user requests a karaoke song, the terminal device first checks whether the requested song has already been stored in the memory device or not. If the requested song has been stored in the internal memory, the terminal device plays the song using a musical instrument digital interface (MIDI) formatted sound source or the like. On the other hand, if the requested song has not been stored in the internal memory device, the terminal device requests the center of the supplier to transmit the song data to the terminal device, and the terminal device plays the song using the song data thus supplied from the center.