Reggae renews itself here, not with musical innovation or even evolution, but simply fresh blooms of the rose. Musical Youth are just that—an appealing black quintet, aged 11 to 16, from industrial Birmingham, England. Passing in and out of the euphonious Jamaican dialect, they sing with unaffected charm and ingenuousness. MTV has helped make a hit of their lilting single from this debut album, Pass the Dutchie ("dutchie" is a Jamaican cooking pot). The next single from the LP ought to be Never Gonna Give You Up, which has an even catchier chorus. Like the Youth, the Melody Makers play and sing with a fetching casualness, but with a more suggestive tropical languor. They should, since they are the four children (aged 8 to 17) of Rita and the late Bob Marley. David, 14, the lead singer, sounds like a potentially significant chip off the old block. Though this is just a two-song extended-play record, What a Plot is a large dutchie full of promise for the future.