Their 1987 LP "Happy Nightmare Baby" was really their only contemporary, official release. Unfortunately, it came during the slow motion wreckage of the once-mighty SST Records, and was not well-promoted. Kendra Smith quit during the following tour, and David Roback recruited Hope Sandoval to replace her. After continuing for a while as Opal, they changed their name to Mazzy Star and finally enjoyed the success they deserved. I don't believe Mitchell ever shared any writing credits during his time in Opal or Mazzy Star (instead, Roback, Smith, and Sandoval were the primary writers), but he was with them since the beginning and his passing deserves to be recognized.
My own story with this LP ties together several of the friends I regularly mention here. It was either my college freshman (87/88) or sophomore year (88/89) and I was shopping at the Blacksburg Record Exchange, which was the "cool" record store. While I was browsing the records, the song "Soul Giver" came on the store's sound system. I was quickly mesmerized and I had to stop and go ask the clerks who was playing. I left with a copy of "Happy Nightmare Baby". In my later professional life I met Butch and learned that he used to work at the Record Exchange; if this was 1987 he might have even been working there that day. I also bought Terry a copy of the LP for Christmas and on returning back home to Newport News for the holidays, I went to Drew's house, where Terry was, and proclaimed to the many people there that I had an awesome new LP that they had to listen to immediately. We did, and Terry was a big fan afterwards.
The LP itself can be triangulated between The Doors, The Velvet Underground, and Black Sabbath. The lineage to Mazzy Star is clear, although this LP lacks the quieter dream pop and alt-folk/country sounds that Mazzy Star would introduce. This LP has several good tracks and a couple that, while not bad, don't quite work for me ("A Falling Star", "She's a Diamond"). But that doesn't matter -- even if the rest of the songs were bad, there's still "Soul Giver", which is as commanding now as the day I first heard it in the Record Exchange; in part because of the strong rhythm from Smith (now retired) and Mitchell (now deceased). And much like I was bursting to share it with Terry, Drew, et al. some 30 years ago, I'm happy to share it with you now.
Standout songs: "Rocket Machine", "Magick Power", "Supernova", "Happy Nightmare Baby", "Soul Giver"
Skip 'em songs: none
Final Score: 8/10 -- "Happy Nightmare Baby" doesn't have accessible songs like "Halah" and "Fade Into You", so casual Mazzy Star fans won't care for it but it's necessary for serious collectors.
Bonus link: a live version of "Soul Giver" (ca. 1988) with Hope Sandoval singing.