Iced Earth's debut album was called Night of the Stormrider. It weaves a pretty dark tale of a mans betrayal by religion, subsequent turn to the dark side and final regrets over the course of nine tracks (46 minutes).

Queensryche's (arguably) best album Operation: Mindcrime. It tells the tale of a young malcontent who becomes involved in an underground revolution as an assassin. This is another that is not just one song, but a story that spans fifteen tracks. One of the best rock operas that was ever pulled off in my opinion.

Manowar's album The Triumph Of Steel has a first track called Achilles, Agony and Ecstasy in Eight Parts. It is essentially a telling of the tale of Hector and Achilles. It's nearly 30 minutes over the eight unique sounding parts.

Ice Nine Kills has now (2) entire albums with tracks inspired by horror movies, but I wouldn't call them long. Their song Meat & Greet would be a great example. It's a retelling of "The Silence of the Lambs".

Animals Without Leaders has a song called CAFO that I just adore. Its pretty long and although it speaks no tale, it's so sonically unique that it feels like it does. Some of those ultra technical metal bands feel like that (to me at least).