Rockin’ Patent – TONUS Inc’s “Music Synthesizer Keyboard”

US Patent No. 3,665,089 – TONUS Inc – Music Synthesiser Keyboard - Patents Rock - Russell IP
  • Rockin’ Patent®: US Patent No. 3,665,089
  • Filed: 17 December 1970
  • In the name of: TONUS Inc
  • Title: Music Synthesizer Keyboard
  • What’s claimed: “In an electronic system, in combination: means for providing a plurality of voltages of different values; means for selecting at least two of said voltages substantially simultaneously; means for providing a reference voltage; means for deriving a difference signal from the values of said reference voltage and one of the selected voltages; means for deriving an output signal from the values of said difference signal and the other of said selected voltages; and means for generating two signals having frequencies in accordance respectively with the values of said output signal and said other of said selected voltages.”
  • Why this patent rocks: This patent appears to relate to the two-voice ARP keyboards for the ARP 2500 and the 3620 keyboard for the original ARP 2600 synthesiser. This synthesiser has been used by a range of musicians from Stevie Wonder and Elton John to bands like Joy Division and The Cure. If you’re curious about the specifications, see here. If you’re interested to know more about the synthesiser, see here for a short documentary on the story of the ARP 2600.

If you’re a patent-savvy music tech business looking for patent help, get in touch with Russell IP here!

The information above is for general interest and information only and does not constitute legal advice.

Share the Post:

Related Posts

IP insurance: an option worth knowing about

By Iain Russell, Patent Attorney and Director at Russell IP (BSc, CPA, EPA, FRSA — 20 years’ experience in computer-implemented inventions and music technology). IP Insurance: An Option Worth Knowing About A question we are sometimes asked, particularly by those new to patents, is what the point is in having a patent if you cannot afford to enforce it, or to defend an allegation that you infringe someone else’s rights. It is a fair concern: patent disputes can be expensive. One option that some businesses may not be aware of is intellectual property (IP) insurance. Important note: Our expertise is

Read More

What Does A New UK Government Study Reveal About AI Patents?

By Iain Russell, Patent Attorney and Director at Russell IP (BSc, CPA, EPA, FRSA – 20 years’ experience in computer-implemented inventions and music technology). What Does A New UK Government Study Reveal About AI Patents? Published: September 2026 | Last updated: September 2026 A recent government-backed study in the UK has found that AI-related patent applications rose from 5.2% of all US patent applications filed in 2014 to 20.3% in 2023. In other words, AI patent applications now make up roughly one in five filings in the US. The finding comes from a study called AI Skills for Life and

Read More

Gain the Competitive Edge

Let's see how we can help protect your IP

Get in touch using the contact form or the phone number below to see how we can protect your IP.

There’s no obligation to sign up for anything.