So if several works were published by the author as one collection, and they have some common theme, it is appropriate to create a collection as a separate work and use the collection’s title in titles of individual works? I am not talking about obvious cases like “Symphonie no. 1: I. Moderato”, but about cases where works in a collection are not closely related.
To make sure I really understand the style guide recommendation, could you please provide a couple of examples when it is not appropriate to create a work for collection? I assume that there should be many such cases if somebody cared to include a special rule against it in the style guide.
I have asked this question because of several collections of works by Frescobaldi. For example, in 1628 he published “Il primo libro delle Canzoni”, a collection of 40 works. In the catalogue each canzona has its own catalogue number, similar to works in Bach’s “The Well-Tempered Clavier”. Is this enough to treat canzonas as parts of a whole and enter their titles like “Il primo libro delle Canzoni: Canzona I detta la Bonvisia, canto solo, F 8.01a”, or is a simpler “Canzona I detta la Bonvisia, canto solo, F 8.01a” more appropriate?