Of all the many missing bits and pieces of Neil Young's swiss-cheese catalog, On the Beach has left the largest hole. Released in 1974 and never before available on CD, it's the final album of what's known as his ''doom trilogy,'' and the cavern-black atmosphere lives up to that dismal billing. The sound is stripped-down and casual, but the vibe is intense. ''I hear that Laurel Canyon is full of famous stars,'' he sings, supposedly in the voice of a Manson Family member, ''but I hate them worse than lepers and I'll kill them in their cars.'' The other three albums -- late-'70s and early-'80s toss-offs also on CD for the first time -- are not essential, but even Young's most mediocre efforts manage plenty of inspired moments.