After giving the Port St Willow album a few spins recently i've realised quite a few of my favourite indie albums (whether 'concept' albums or not) repeat ideas and riffs throughout, and/or make references between songs. like:

The Antlers - Hospice
Neutral Milk Hotel - Aeroplane..
Lift To Experience - Texas Jerusalem Crossroads
Phosphorescent - Aw Come, Aw Wry

Funny that, isn't it? What are some other albums that do the same?