Boasting a perfectly calibrated vocal quartet, an aggressive rhythm section, and stacks of Rhodes, Rolands, and Hammond keyboards, Mind & Matter were instrumental in creating the Minneapolis Sound. Tracked in 1977, this bundle of never-before-released basement demos throw Jimmy Jan Harris' beloved Philadelphia Sound into an unfinished root cellar, pelting it with Clavinet attacks, disco skats, and infectious hooks. Named for the street address of its underground uptown genesis, 1514 Oliver Avenue (Basement) is an organic alternative to a late-'70s Prince songbook gone increasingly synthetic.