You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "a b a c a b a is an example of which form from the classic period?" whose answer is rondo.
Each document should contain about 30 words, and these documents should contain useful information.

Query: classical music forms a b a c a b a
Useful Output:

Doc 1: I was thinking of having the material in the first movement be a typical ABACABA then pick the previos material to make an ACAB form.
Doc 2:  form in classical music. Rondo is a musical structure that features  ABACABA, highlighting how these structures function within compositions.
Doc 3: The rondo comprises a musical form that has actually made up the backbone of classical composition, from the Baroque to Classical and early Romantic periods.
Doc 4: For this reason, works that are in Ternary forms often repeat the A section - so, AABA. A Minuet and Trio is usually a good example of Ternary
Doc 5: The classical rondo structure often takes one of the following forms: ABACA, ABACADA, or ABACABA. This predictable return to the 'A' theme