"Drumscape" was the first music game based on Devecka Enterprises' 1996 patents and it was released in 1997 prior to Konami's first "Beat Mania" game. Devecka Enterprises has claimed that its patents cover not only drumming games but all music games (including but not limited to "Guitar Freaks", "Guitar Hero", "Rock Band", and "Dance Dance Revolution"), however because its concept is very basic and that prior non-patented MIDI drumsets have been used as training tools and as input, the patent's validity has been called into question. Outside of the United States, Devecka's patents have been successfully challenged due to these claims. Neither Devecka nor MTV, for example, have challenged Konami or other music game companies (such as Harmonix for its "Rock Band" series or Namco for its "Taiko no Tatsujin" drumming game).