Instruct: Classify a given review into positive or negative sentiment.
Query: Worst Chicago album to me!

I can see why I saw the cassette version of this album in $1.99 bins in the '90s. Chicago's 21st album was the worst album to me, easily the worst I've heard from them. The album sounds so boring, and the performances sound so uninspiring. Even the Diane Warren-written song sounds lousy, typical of her sappy ballad pap! There's not one memorable song on here, compared to classics like If You Leave Me Now, Love Me Tomorrow or others. Don't hear a lot of their famous horns, only keyboards and pop songs. And Ron Nevison produced this overproduced, overwrought fluff? If Chicago, with their extensive catalog, even thinks about performing one song from this album live, you might want to walk out of the theater to get concessions. They are too multi-talented a band to let themselves get through this commercial flop that this album was in 1991!