I've been listening to Astral Weeks a lot recently. I lost my copy ages ago and finally found it (inside another CD box), and every since I've been making up for lost time by playing it again and again.
It's a magnificent album. Every track is superb. The last track, though, is a marvel. Slim Slow Slider is a slice of horrible beauty. As a conclusion to a complex album it couldn't be better. It's also, I suspect, a brilliant example of ex tempore storytelling. Certainly, the recording of the album was done in a freeform way, with Morrison allowing his musicians to follow his lead.
Slim Slow Slider is a song about a lost love. But it morphs into something very dark, and we realise the girl in the song is using drugs. Near the end, Morrison sings "I know you're dyin' babe, and I know you know it too." It's a remarkable shift, but entirely fitting. It flows perfectly from the music. Immediately, there is a great depth to the song. And, having given us that shattering conclusion, the song ends, amost literally with a shudder. The music rumbles to a halt. It is a perfect ending.
Apparently, when recording this ending, it went on for ten minutes or so, but it was all cut in the editing process. A good thing, too. It is the best ending of any song I know. It is horrifying.