COUNCIL BLUFFS - The Black Keys have undergone an amazing evolution from a two-man band playing before small crowds at clubs to a Grammy-winning rock band packing arenas.

Only four years ago, the band headlined a show at the nearly 500-person capacity Slowdown. On Wednesday night, the Black Keys played to a packed house of thousands at the Mid-America Center.

Venues and crowds aren't the only things that have gotten bigger for the band. It has expanded its touring lineup, beefed up its lights and video, hired a huge crew of techs and roadies and created a bevy of new music.

Over a 90-minute set, the bluesy garage rock duo - with two extra musicians on backup - played 20 songs that included old favorites such as "Strange Times" and tunes from the Keys' latest album, "El Camino," that included "Lonely Boy" and "Gold on the Ceiling."

For me, the band's latest material sounds a bit too polished.