An excellent, if somewhat specialized collection, Bump'n'Grind delves into the archive in search of performances that could, maybe even should, have made the Unchained series, but ultimately didn't. Working mixes of familiar material, unedited snapshots of recording sessions, false starts, and the occasional demo fall out of the speakers, all in excellent sound quality and all with something to recommend them to the listener. The full five-minute take of "The Groover," with the guitars wailing on long after the traditional fade; a thunderous run through "Jitterbug Love," an almost reggae-tinged thud through "Telegram Sam," a positively grinding "20th Century Boy," and all leading up to 12 minutes of "Children of the Revolution," an experimental jam that allows the entire studio to throw something into the pot. An unmixed "Metal Guru," with the acoustic guitars up high, but still awaiting saxophone, strings and backing vocals, is a joy to behold, while "Thunderwing" swaggers along beneath a honking sax, and extra-added handclaps. Elsewhere, there's an early (1987) take on "The Soul of My Suit," while prototype takes on "Laser Love" and "Dreamy Lady" (here titled "Silver Lady") chase the story deeper into Bolan's career, while the liner notes deliver all the background to each recording that you could require. Again, you probably need to be a dedicated specialist to truly require this collection. But if you are looking for yet another alternate vision of some of the most important music of the 1970s, Bump'n'Grind will certainly fit the bill.