# How Laurens Hammond Invented the Electric Organ

> Laurens Hammond's 1934 patent for an electrical musical instrument that used spinning tone wheels to generate sound, forming the basis of the iconic Hammond organ.

- **Patent:** US 1956350
- **Original title:** Electrical musical instrument
- **Owner:** Individual
- **Granted:** 1934
- **Status:** Public domain (expired)
- **Times cited:** 35
- **Field:** mechanical, consumer_electronics

## What it does

The patent describes a system for generating musical tones using rotating electromagnetic tone wheels. As these metallic wheels spin near electromagnetic pickups, they create alternating currents that correspond to specific musical frequencies. These signals are then amplified and sent to a speaker to produce sound, effectively replacing the heavy pipes and air-driven bellows of traditional organs with compact electronic components.

## What it does NOT cover

- Does not cover digital synthesis or software-based sound generation.
- Does not cover modern MIDI-based keyboard controllers.
- Does not cover instruments that rely on vibrating strings or reeds.

## The clever bit

By using precise electromagnetic induction from spinning wheels, Hammond turned mechanical motion into a pure, controllable electrical signal, bypassing the need for physical air columns.

## Real-world examples

1. Hammond B3 Organ
2. Hammond C3 Organ
3. Vintage electric organs used in classic rock and soul music

## Why it matters

This invention allowed churches and venues to have the rich, powerful sound of a pipe organ without the massive cost and physical space requirements. It became the backbone of jazz, blues, and rock music for decades, defining the sound of the 20th century.

## Frequently asked questions

### What does How Laurens Hammond Invented the Electric Organ cover?

Laurens Hammond's 1934 patent for an electrical musical instrument that used spinning tone wheels to generate sound, forming the basis of the iconic Hammond organ.

### Who owns patent US 1956350?

Individual owns this patent, granted in 1934.

### When does this patent expire?

This patent has expired and is now in the public domain — anyone can use the invention freely.

### What is patent US 1956350 cited by?

This patent has been cited by 35 later patents that build on its ideas.

### What problem does this patent solve?

This invention allowed churches and venues to have the rich, powerful sound of a pipe organ without the massive cost and physical space requirements. It became the backbone of jazz, blues, and rock music for decades, defining the sound of the 20th century.

### What does this patent NOT cover?

Does not cover digital synthesis or software-based sound generation.

**Full plain-English explainer:** https://patentbrief.org/patent/us/1956350/hammond-organ

**Original patent:** https://patents.google.com/patent/US1956350

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_Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._


## Related patents

Semantically similar inventions in the PatentBrief corpus:

- [How the Frying Pan Guitar Created the Electric Guitar](https://patentbrief.org/patent/us/2089171/electric-guitar-frying-pan) — George Beauchamp's 1937 patent for the first commercially successful electric guitar, which used a magnetic pickup to turn string vibrations into electrical signals.
- [How the Theremin Makes Music Without Touching Anything](https://patentbrief.org/patent/us/1661058/theremin-leon-theremin) — Leon Theremin's 1928 patent for an electronic musical instrument that generates sound based on the proximity of a performer's hands to metal antennas.
- [How Robert Moog Used Transistors to Shape Synthesizer Sounds](https://patentbrief.org/patent/us/3475623/moog-synthesizer-ladder-filter) — A 1969 invention by Robert Moog that uses the internal resistance of transistors to create the iconic filters that define the sound of analog synthesizers.
- [How Georges Claude Invented the Neon Light](https://patentbrief.org/patent/us/1125476/neon-lighting-claude) — A 1915 patent describing the use of neon gas in sealed glass tubes to create bright, colorful light for signs and illumination.
- [How Early Industrial Food Mixers Used Planetary Gear Systems](https://patentbrief.org/patent/us/1264128/stand-mixer-kitchenaid-johnston) — A 1918 patent for a heavy-duty industrial mixing machine that used a specific gear arrangement to rotate a beater while simultaneously moving it around the bowl.