In 2008, Konami filed a patent lawsuit against Harmonix (and MTV, and Viacom).
https://lastchance.cc/konami-suing-harmonix-over-rock-band-5024079%3C/a%3E%3C/p%3E
Harmonix, which worked with Konami in 2003 to create Karaoke Revolution, developed Guitar Hero in 2005 — years after Konami had released its own guitar game GuitarFreaks in Japanese arcades. Likewise, Konami’s DrumMania seemed to be echoed in Harmonix’s Rock Band games.
That lawsuit has been settled. Both companies have agreed to dismiss “all claims and counterclaims” in the suit. According to Bloomberg, the terms of the settlement were not disclosed.
Japan’s Konami, Viacom Settle Fight Over Music-Video Games, `Rock Band’ [Bloomberg via Edge]
