And the frustrated singer vows that if the concert film doesn't hit shelves soon, he'll take action himself.

Guitar icon Montrose shot himself in March this year. He had suffered from clinical depression for much of his life, and the deaths of his uncle and dog within weeks of each other are understood to have been factors in his decision to commit suicide.

The following month, surviving Montrose members Hagar, Bill Church and Denny Carmassi fronted a memorial event that also starred Joe Satriani, Neal Schon, Tommy Thayer, Jimmy DeGrasso and many others.