Can the roots of today's interactive new media art be traced to the thoughts of 19th century composer Richard Wagner? And did video artist Nam June Pail foresee a new breed of "global information art" back in 1984, long before Net art made its debut? Read the just-released "Multimedia: From Wagner to Virtual Reality" (W.W. Norton & Co.) and find out. A Web site (on artmuseum.net) compliments the book.