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(Roberto Legaspi del Rosario)
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Born on <time datetime="1919-06-07">June 7, 1919</time>, in <a href="https://kahimyang.com/articles/3190/pasay-citys-story-a-historical-overview" class="news_link">Pasay City</a>, Philippines, Del Rosario was not an engineer by training. He was a musician who learned to play instruments by ear. His ability to listen and improvise helped him create machines that allowed ordinary people to feel like professional singers. His company, the <b class="lt-bold">Trebel Music Corporation</b>, became a household name in the Philippines, and his legal victories proved that Filipino innovation could stand up to global competition.   
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<h2>
Early Life and Musical Roots
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Roberto del Rosario was the son of <b class="lt-bold">Teofilo del Rosario</b> and <b class="lt-bold">Consolacion Legaspi</b>. Growing up in Pasay City, he was surrounded by music. However, he never took formal music lessons. He could not read sheet music. Instead, he mastered the piano, drums, marimba, and xylophone by <b class="lt-bold">"ouido"</b>, or playing by ear. This meant he listened to a song and figured out how to play it on his own.   
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This background is important because it shaped his approach to invention. He did not view music as a strict set of rules written on paper. He saw it as something to be enjoyed and shared. He wanted to make music accessible to everyone, not just those who had years of training.
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During World War II and the years that followed, the Philippines had a vibrant nightlife scene. Del Rosario became a key figure in this world. He was a founding member of a famous amateur jazz band called <b class="lt-bold">"The Executives Band Combo"</b>. This was not an ordinary group. It was led by <a href="https://kahimyang.com/kauswagan/articles/2631/raul-manglapus-more-active-in-america-than-ninoy-aquino-in-opposition-to-marcos" class="news_link">Raul Manglapus</a>, a prominent politician, and Francisco "Bobby" Mañosa, a famous architect.   
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The band played all over the world. They performed with jazz legends like Duke Ellington and even played for political figures like <a href="https://en.wikipedia.org/wiki/Bill_Clinton" class="news-link-ext" target="_blank" rel="noreferrer">Bill Clinton</a> years later. Playing drums and piano in this band gave Del Rosario a front-row seat to how audiences reacted to music. He saw that people didn't just want to listen; they wanted to participate.   
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<h2>
The Trebel Music Corporation and Early Inventions
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Del Rosario turned his love for music into a business. He founded the Trebel Music Corporation in Taytay, Rizal. The name "Trebel" was a play on his nickname, "Bert" (spelled backward), combined with "El" for his wife, Eloisa.   
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At Trebel, he manufactured pianos and harpsichords. But he was always tinkering with new ideas. Before he invented the Karaoke machine, he created the <b class="lt-bold">"One-Man Band"</b> (OMB) in 1972. This was a special piano that had a synthesizer, a drum machine, and bass pedals built into it. It allowed one person to play the melody, the rhythm, and the bass line all at the same time.   
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He also invented other tools to help musicians. He created the "Piano Tuner's Guide", which used lights to help people tune pianos easily. He also made the <b class="lt-bold">"Voice Color Code"</b> (VCC), which helped singers find the right key for their voice. These inventions showed his main goal: to make music easier to perform.   
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<h2>
The Invention of the Sing-Along System
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In the 1970s, Del Rosario began working on his most famous invention. He used a technology called <b class="lt-bold">"Minus One"</b>. This term referred to music tracks that had the vocals removed, leaving only the instrumental accompaniment. While "Music Minus One" records already existed for people learning to play instruments, Del Rosario wanted to use it for singing.   
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He developed a machine that combined a cassette tape player (to play the Minus One tracks), an amplifier, a speaker, and a microphone mixer. The most important feature he added was "reverb" or echo. This effect made an amateur singer's voice sound fuller and more professional, like they were singing in a concert hall.   
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He called this the "Sing-Along System" (SAS). He finalized the design between 1975 and 1977. Unlike Japanese inventors who were making similar machines at the same time, Del Rosario decided to protect his invention legally. He applied for a patent in the Philippines.
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He was granted Letters Patent No. UM-5269 on <time datetime="1983-06-02">June 2, 1983</time>, and an improved patent, UM-6237, on <time datetime="1986-11-04">November 14, 1986</time>. These patents were for a "Utility Model", which protects a specific combination of tools that provide a practical use. His patent described a compact cabinet that held all the necessary sound equipment together.   
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<h2>
The Debate: Who Invented Karaoke?
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There is often a debate about who really invented karaoke. The word "karaoke" comes from Japan, meaning "empty orchestra". A Japanese musician named <a href="https://en.wikipedia.org/wiki/Daisuke_Inoue" class="news-link-ext" target="_blank" rel="noreferrer">Daisuke Inoue</a> built a machine called the "8-Juke" in 1971. Inoue's machine was coin-operated and meant for bars. However, Inoue famously did not patent his invention. He used existing car stereos and coin boxes and did not think to claim the rights to the combination.   
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Roberto del Rosario, on the other hand, did secure the patent. While Inoue created the business model of renting machines to bars, Del Rosario invented the home appliance version. Because Del Rosario held the patent, he is legally recognized as the inventor, especially in the context of intellectual property law.   
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Roberto del Rosario: The Filipino Father of Karaoke (Born June 7, 1919)