Anyone who’s having trouble "getting" Joni Mitchell ought to pick up Lloyd Whitesell’s book "The Music of Joni Mitchell." He analyzes every track in her catalog in terms of specific parameters: melody, lyrics/poetry, harmonic structure, personae, arrangement, album concept, etc. There are three appendices that each consider one of her releases in its entirety as a concept album.
There are other books that analyze Joni’s music, but none I’ve found that are as readable, insightful, engaging (not just a dry, academic musicological analysis), and as much fun to read while listening the recordings themselves.
Highly recommended to anyone with a layperson’s background in music theory, poetry, or pop music in general.
From the Amazon page for the book: "The Music of Joni Mitchell offers a comprehensive survey of her output, with many discussions of individual songs, organized by topic rather than chronology. Individual chapters each explore a different aspect of her craft, such as poetic voice, harmony, melody, and large-scale form. A separate chapter is devoted to the central theme of personal freedom, as expressed through diverse symbolic registers of the journey quest, bohemianism, creative license, and spiritual liberation."
I found that, after reading the book, some of my least-favorite Joni albums, like "Seagull" and "Don Juan", became my favorites. I was amazed by how much depth and sophistication was packed into even her earliest songs, such as "Dawntreader" from the first album.