Kurt Cobain's appearance in the latest "Guitar Hero" video game is not hitting the right notes with the surviving members of Nirvana.

Krist Novoselic and Dave Grohl said in a joint statement Thursday that they were "dismayed and very disappointed" that an avatar of the late Nirvana frontman could be used to play songs by other artists.

"While we were aware of Kurt's image being used with two Nirvana songs, we didn't know players have the ability to unlock the character," they said. "This feature allows the character to be used with any kind of song the player wants. We urge Activision to do the right thing in 're-locking' Kurt's character so that this won't continue in the future."

Cobain's widow, Courtney Love, had been lashing out on Twitter this week about her late husband's inclusion in the game, calling it vile and claiming she would sue Activision, the game's publisher. Love claimed she never approved Cobain's digital likeness, and that she thought the grunge rocker would despise the rhythm game "let alone this avatar."

Activision said in a statement Thursday that they secured the necessary licensing rights from the Cobain estate in a written agreement signed by Love to use the singer's likeness as a fully playable character in "Guitar Hero 5," which includes "Smells Like Teen Spirit" and "Lithium" among its 85 tracks that can be played with instrument-shaped controllers.

Other real-life rockers featured in the latest edition of the popular rhythm game franchise for the Xbox 360, PlayStation 2, PlayStation 3 and Wii include Carlos Santana and Johnny Cash. Previous "Guitar Hero" editions have featured the likenesses of Jimi Hendrix, Billy Corgan, Ted Nugent, Sting, Ozzy Osbourne, Travis Barker and members of Aerosmith.