Instruct: Classify a given review into positive or negative sentiment.
Query: hidden classic

I purchased Bartz's "Blue Chronicles" a few years back and liked that a lot, but this album, recorded in the mid-1970s, is the real gem. It's not long, but it's packed with great songs and a stellar bunch of musicians who let loose and lay down a wicked groove. Any fans of 70s-era Donald Byrd or Grover Washington will like this jazz-funk hybrid. Great stuff!