Janis Joplin, Janis (Columbia/Legacy) (iTunes / Spotify / Amazon)

A surprise digital vault drop from the late blues singer, this is the double album from 1974 that offered a soundtrack to the film of the same name. You get some of her most famous singles, with Big Brother and The Holding Company and on her own, plus live cuts, interview snippets, and - for the entirety of the set's second disc - more than a dozen early performances cut between 1963 and 1965. Part greatest hits, part, archival study, but all Janis and her unmatched vocals.

David Bowie, I'm Only Dancing (The Soul Tour 74) (Parlophone) (iTunes / Spotify / Amazon)

Released for Record Store Day last year, this concert release premieres the first recordings from the second leg of Bowie's Diamond Dogs tour, which heavily anticipated the sound, arrangement and material of the following year's Young Americans (complete with several of the musicians heard on the album, including saxophonist David Sanborn and a cadre of backing vocalists anchored by a young Luther Vandross). If you missed this on disc, now's a great time to catch it.

Mark Morrison, Return of the Mack (#25ROTM Deluxe Edition) (Warner Music U.K./X5) (iTunes / Spotify / Amazon)

Soul singer Morrison's 1996 debut spun off a raft of Top 10s in his native U.K., but only one in America: the thumping title track, which reached No. 2 on the Billboard Hot 100. But those other singles mean plenty of opportunities for rare remixes or future bonus tracks - which happened on a handful of digital EPs and now this sprawling digital expansion of the record that now clocks in at five hours of music. That's mega Mack!