Roberto del Rosario (1919–2003) was the president of the now-defunct Trebel Music Corporation, a founding member of the Filipino amateur jazz band "The Executives Band Combo," and, in 1975, the inventor of the Karaoke Sing Along System.

Known as "Bert," del Rosario patented more than 20 inventions during his lifetime, making him one of the most prolific of Filipino inventors.

Del Rosario is one of several people who are associated with the invention of a karaoke machine. Karaoke is a compound Japanese word from "karappo" meaning "empty" and o-kestura meaning "orchestra." Sometimes translated as "empty orchestra," the phrase means something closer to "the orchestra is void of vocals."

The Sing Along System

Roberto del Rosario invented his version of a karaoke machine between 1975 and 1977, and in his patents (UM-5269 on June 2, 1983 and UM-6237 on November 14, 1986) he described his sing-along system as a handy, multi-purpose, compact machine that incorporates an amplifier speaker, one or two tape mechanisms, an optional tuner or radio, and a microphone mixer with features to enhance one's voice, such as the echo or reverb to simulate an opera hall or a studio sound. The whole system was enclosed in one cabinet casing.

The main reason we know of del Rosario's contribution is because he sued Japanese companies for patent infringement in the 1990s.

In the court case, the Philippine Supreme Court decided in del Rosario's favor. He won the legal recognition and some of the money, but in the end, the Japanese manufacturers reaped most of the benefits by later innovations.

According to thoughtco.com

Source: https://www.thoughtco.com/roberto-del-rosario-inventor-1991725