Jani Lane to be Honored By Warrant at Tonight's Concert

Jani Lane's former band will pay tribute to the fallen singer at their concert tonight in North Dakota ... TMZ has learned.

Guitarist Erik Turner -- who co-founded the band -- tells us, "We will be making a tribute before we play the song 'Heaven' tonight."

He adds, "We never thought that when the song 'Heaven' was written we would be playing it someday in the memory of Jani's untimely death. This is a very sad day for rock and roll. One of the great things about music is that it lives on forever."

Lane penned the song "Heaven" back in 1989 -- and it's said to be the band's most commercially successful single.