I think that much of Rand's discussion of Romanticism is beside the point, speaking historically. Rand's conception could be described as "Romanticism: The Unknown Ideal", because what she describes bears little resemblance to much of Romantic art and (to the extent it is true of historical Romanticism) applies mainly to the Romantic novel and a little bit to Romantic drama (not even the short story, really). She says nothing about Romantic poetry (or about poetry in general), painting, and sculpture, and very little about Romantic music except to mention that she likes some piano concertos by Rachmaninoff and Tchaikovsky, who are late-Romantic nationalists more than they are Romantic innovators like Beethoven, Chopin (though he is more sui generis than strictly Romantic, I think), and Berlioz. Her idea that "Romanticism is a category of art based on the recognition that man possesses the faculty of volition" boils down to claiming that Romantic novels and plays emphasize plot and value-conflicts, which could be said of Sophocles just as much as of Hugo. For myself, I don't find much of value in Rand's analysis of Romanticism (though she does say some interesting things about volition...).
I find Rand's definition of Romanticism problematical because it really applies only to novels and plays (at least on one interpretation). What does the recognition that man is a volitional being have to do with painting, poetry, music, sculpture, dance? In fiction, Rand connects the recognition of volition with an emphasis on plot (i.e., on chosen action) -- this is the sense in which I say that her conception of Romanticism applies to Sophocles just as well as to Hugo. She pretty much says that the essence of romantic fiction in contrast with naturalism is the fact that romantic writers choose their subjects, i.e., their plots and characters, while naturalist writers write as though the events and characters of their novels should reflect current realities in an almost journalistic way, without idealization or stylization or the exercise of selectivity on the part of the artist. As I noted in my essay A Philosophy for Living on Earth (footnote 6), this view comes dangerously close to denying that naturalism is art at all, because on her theory the essence of art consists in stylization. But naturalistic art is art -- it's just art that attempts to deny the selectivity of art, so that the artist shirks his responsibility to exercise choice in regard to subject and lets "society" do the choosing. (This is perhaps true of naturalism in literature in the late 19th century, but there is another sense of naturalism in art history, as for instance in the naturalistic sculpture of the Hellenistic age, which did not idealize the subject to the extent that classical Greek art did, instead focusing on the distinctive or idiosyncratic characteristics of the individual subject -- in this sense naturalism means "true to life" or even individualistic.)
I also think that Rand's conception of romanticism goes astray when one makes too close a connection between volition and action. My interpretation of Objectivism's philosophical anthropology is that there are four essential powers or capacities of the human individual: thought, volition, action, and feeling (cf. the above-referenced essay). I see volition as essentially the power to exercise selectivity of attention, not as the power of choice regarding action -- as asking "what shall I attend to?", not "what shall I do?" If this is true (I can argue for it separately), then other art-forms can be romantic in Rand's sense, because every art-form provides a field for the exercise of selectivity. Of course, selectivity means individual selectivity, which I think comports well with the individualism (the aesthetic individualism, not necessarily the ethical individualism) of most romantic artists -- the focus on personal perspective and experience, on individual action and feeling (the former mostly in novels, the latter in music and poetry especially), on personal (as distinct from political) freedom, on originality with regard to subject and style, and so on. I think this comes close to a notion of "romantic individualism", although there is the caveat that the individualism is often more aesthetic than ethical -- although the ethical element is there, too, especially in fiction and in the exploration of what individuals will do in a free society.
So I guess I see two senses of romanticism-as-art-that-recognizes-volition, depending on one's conception of volition. Volition-as-choice-of-action leads to romantic literature as plotted literature, while volition-as-choice-of-attention leads to romantic art as aesthetic individualism.
Traditionally, romanticism has been contrasted with classicism on the historical "front end"; Rand also contrasts it with literary naturalism on the historical "back end". When I said in my previous messages that Rand's conception of romanticism could apply just as well to Sophocles as to Hugo (on one interpretation), I was in part pointing to an interesting fact about Rand, which is that her artistic tastes are all over the map and are not canonically romantic. For instance, she heaps high praise on the sculpture of classical antiquity and of the renaissance, but she dislikes classical drama and renaissance music. She has no use for Bach even though his music is eminently rationalistic in the good sense of that term (I'm listening to Bach's Well-Tempered Clavier at the moment). She hates Beethoven even though he was the seminal figure of romantic music. She (presumably) dislikes romantic painting and would have hated most of Victor Hugo's watercolors, IMHO. She loved Vermeer and at least the style of Dali, even though neither was a romantic (Vermeer was a realist and Dali a surrealist). She thought the Russian Symbolist poet Alexander Blok was a magnificent poet stylistically (although she disliked his metaphysics), even though Symbolism as a literary movement was diametrically (perhaps I should say "metrically"?) opposed to romantic tendencies. She liked modern architecture (Frank Lloyd Wright, Eli Jacques Kahn, etc.) but disliked all other modern art. Can one find a consistent theme in all the works or styles or artists she liked? Yes -- Ayn Rand liked them.
In general, there are several qualities that Rand seemed to prefer in art. She liked grandeur (cf. Introduction to Ninety-Three, RM 158; The "Inexplicable Personal Alchemy" in The New Left, p. 117; etc.) -- thus her love of Hugo's novels and plays, of large-scale works like Rachmaninoff's Second Piano Concerto and Tchaikovsky's First; you would not see her express admiration for small-scale works such as Hugo's poems, Rachmaninoff's Preludes for piano, or Tchaikovsky's string quartets (I think this is one reason she did not appreciate poetry). She liked the heroic -- indeed I think her own approach to art is perhaps best described as "Heroic Symbolism" (for the Symbolism part, see RM 126, where she says that symbolism consists in "the presentation of a metaphysical view of man, as opposed to a journalistic or statistical view" -- is this not her artistic credo?). She liked beauty, often of a rather superficial quality (Rachmaninoff's Second Piano Concerto, for example, is considered something of a "slick" piece of music, and was so considered even by its composer, I believe). She liked high drama and even seeming paradox (as is evident in her own work). She liked full clarity, at least in the visual arts (thus her love of Vermeer and Dali, and her dislike of "the so-called 'painterly' school, from Rembrandt on down" -- RM 41) and also in literature (cf. her comparison of Mickey Spillane and Thomas Wolfe, RM 94ff.).
Is there one thread that ties all these characteristics together? Does the sum of them equal romanticism in the sense of "art-that-recognizes-volition"? I think not.
Rand's thought on art is often subjective in the sense of irremediably personal. The personal and the philosophical are horribly mixed here, and it's difficult to tease out one from the other. Is Rand's concept of romanticism really just a personal credo with no historical validity or application but to her own writings -- and even there not as much to her early work as to her later work? Quite possibly so.
Interestingly, I prefer much that Rand dislikes. In general (there are exceptions), I prefer the small-scale and intimate to the large-scale and "grand" -- I prefer poetry to the novel, solo and chamber music to concertos and symphonies, etc. My tastes in music are so broad and latitudinarian (from Palestrina to the Police, from Bach to bluegrass, from Rachmaninoff to reggae, from Dvorak to Dylan) that Rand would find them unintelligible. I like many paintings that do not exhibit sharp edges and bold relief, and my favorite painter is probably Joaquin Sorolla, who was somewhat impressionistic in his style (although Vermeer is a very close second). I have no strong need for the dramatic and the theatrical. Although I like heroic art as much as the next objectivist, I like much art that is not heroic and I do not think that the portrayal of heroism is the raison d'etre of art (I listen to Bach more than Rachmaninoff). I often prefer excellence in craft to the explicit message or philosophy of works of art (which is why I prefer A.E. Housman to Berton Braley, to pick a random example from my poetry shelf).