Any singer worthy of their talent can strip a song down to its bare bones and successfully perform it without enhanced instrumentation or recording.
Whether Prince would have allowed this nine-song collection of previously unheard home studio cassette recordings to be released were he alive is a moot point (rough guess: unlikely), because what we have are unadorned performances originally recorded for his ears only. For all that, this is a fascinating assortment.
Recorded before Purple Rain (album and film) showered him with immense commercial success, there is intimate gentility here that becomes such a fine songwriter.
Songs such as Purple Rain, Joni Mitchell's A Case of You (sketch versions each), 17 Days and Strange Relationship would appear on future works; much rarer are the likes of Why the Butterflies and Cold Coffee and Cocaine. The latter is gruff, frenetic; the former is a classic Prince song in waiting.
Best of all, however, is Mary Don't You Weep, a thrilling, grandstanding version of a traditional negro spiritual song dating from the US civil war.
For that alone, Piano & a Microphone is an essential, if occasionally vexing eavesdropping experience.