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PatentBrief
US 1661058Freedom to Build
Public domain since 1945

You can freely build on How the Theremin Makes Music Without Touching Anything

This patent expired in 1945. Every claim — 0 independent, 0 dependent — is now unenforceable. Anyone can use, reproduce, manufacture, sell, or offer for sale this technology without a license.

Original assignee

FIRM OF M J GOLDBERG und SOHNE

Patent granted

1928

Expired

1945

Forward citations

40

What this patent covers

The device uses two metal antennas to control sound parameters through the player's body capacitance. As a performer moves their hand near the vertical antenna, the circuit changes its frequency to alter the pitch. Simultaneously, moving a hand near the horizontal loop antenna changes the amplitude or volume of the sound. This allows for continuous, fluid control of musical notes without physical contact between the player and the instrument.

What is now free to use

All 0 claims of US 1661058 are in the public domain. Specifically:

    The 0 dependent claims add narrowing limitations and are also free.

    What is NOT covered

    Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.

    • Does not cover instruments that require physical keys or strings to be pressed.

    • Does not cover digital synthesizers that rely on microprocessors rather than analog vacuum tube oscillators.

    • Does not cover sound generation via optical sensors or infrared beams.

    Who is building on this today

    Companies like Moog Music continue to manufacture instruments based on these core principles. Modern touchless interface designers also draw inspiration from the capacitive sensing methods pioneered here.

    Products built on expired version of this technology

    The classic Moog Theremin

    Soundtrack for the 1945 film Spellbound

    The Beach Boys' Good Vibrations

    How to cite this patent in your documentation

    FIRM OF M J GOLDBERG und SOHNE. US Patent 1661058. Method of and apparatus for the generation of sounds. Granted 1928, expired 1945. Now in the public domain.

    Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.

    PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.

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