Country Joe McDonald hasn’t made an aesthetically or commercially successful album in years, which may help to explain why one of the songs on Rock and Roll Music from the Planet Earth is titled “Bring Back the Sixties, Man.” Be that as it may, this LP typifies his recent efforts in that it intersperses numerous disappointments with just enough good material to make those who’d count him out think twice. The number-one problem is the muddy, colorless production, which obscures the cutting edge in McDonald’s voice and robs the bulk of the music of any personality. If you skip over such tedious efforts as “Coyote” (not the Joni Mitchell tune) and the Hallmark-verse-styled “Y-O-U,” however, you will find a few reasons to be optimistic about his future work.