[Thanks to all who replied to my question about what is a symphony written
in 'cyclical' style (or whatever the appropriate phrase is)!]

The Liszt B minor sonata was put forward to me when I was a student as
an example of "metamorphosis of themes".  I gather that's a different idea
in some technical aspects, but the idea of thematic unity throughout the
composition, albeit at different levels, is clearly a major ideal of the
Romantic period.

BTW, I was excited *to hear* the thematic unity of Wagner's Ring.  Deryck
Cooke, in his Introduction to the Ring shows how a large proportion of the
themes of the Ring derive from the opening Nature theme of Das Rheingold,
the horn arpeggio.  Of course the theme of the Rhine itself is an obvious
close relation, but so are the themes of the World Ash, Wotan's Staff /
Spear, the sword Notung, the Goddess Erda, and even the falling "twilight
of the gods" theme (a modification of the inversion of the rising Nature
theme).

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