Soundgarden will warm up for its Aug. 8 headlining performance at Lollapalooza in Chicago's Grant Park with an Aug. 5 show at the city's 1,400-capacity Vic Theatre.

Tickets are exclusively available to members of the band's Soundgarden World fan organization. For information on how to sign up as well as rules and restrictions, click here.

One of the most popular rock bands of its era, Soundgarden broke up in 1997. Frontman Chris Cornell announced the Seattle-based group was re-forming on Jan. 1 of this year, and the foursome played its first reunion show together on April 16 at the hometown Showbox at the Market.

Sources say the group, which also features guitarist Kim Thayil, bassist Ben Shepherd and drummer Matt Cameron, has been rehearsing throughout the spring and summer ahead of Lollapalooza, but that no decision has yet been reached on how extensive the reunion will be.

There will be new music for fans to hear before too long, however. A previously unreleased Soundgarden song, "Black Rain," will appear in the next installment of the "Guitar Hero" videogame franchise, "Warriors of Rock," due in September. It is unknown if the song was newly recorded or if it is an unreleased track from when the band was previously active.