Patent ID: 7129408

Claim:
A music performance system for synchronously producing music sound and visual images, comprising: plural communication channels independently of one another, and selectively assigned pieces of music data representative of music sound, pieces of first timing data representative of respective occurrences of said pieces of said music data, pieces of periodical data each representative of a sign of a time period, pieces of second timing data representative of respective occurrences of said pieces of periodical data and pieces of visual data representative of at least an attribute of visual images for propagating therethrough without any guarantee of a time consumed in the propagation; a first audio-visual station including a music data source outputting said pieces of music data together with the associated pieces of first timing data and said pieces of second timing data to one of said plural communication channels, a visual data source outputting said pieces of visual data and said pieces of periodical data to said another of said plural communication channels, a time keeper producing said pieces of periodical data at regular intervals, connected to said music data source and said visual data source and determining a first time at which each of said pieces of music data occurs and a second time at which each of said pieces of periodical data occurs, thereby selectively supplying said pieces of first timing data, said pieces of second timing data and said pieces of periodical data to said music data source and said visual data source; and a second audio-visual station connected to said plural communication channels so as to receive said pieces of music data, said pieces of first timing data, said pieces of periodical data, said pieces of second timing data and said pieces of visual data, and including an internal clock measuring a third time asynchronously with said time keeper, a clock setter pairing said pieces of second timing data with the associated pieces of periodical data to see whether or not a time difference between arrivals thereat is ignoreable, and setting said internal clock right on the basis of said pieces of second timing data and said time difference if said time difference is not ignoreable, a visual image generator supplied with said pieces of visual data so as to produce said visual images and a music sound generator comparing said pieces of first timing data with said third time so as to produce said music sound synchronously with said visual images.