Richard Halley is another of the book's legendary figures. At the beginning of the novel, he is almost not even a "real" character at all. We hardly hear his name when it's not linked to his concertos, which act as motifs in the novel. In a way, Halley's music is more important than he is. But since Galt preaches that a person's work reflects who they are, Halley is, through his music, one of the most important figures in the novel. (To read more about music in the novel, check out the "Symbols, Allegory, Imagery" section.)
Halley's music is particularly important to Dagny. Her character is introduced in conjunction with Halley and his music:
She thought dimly that there had been premonitory echoes of this theme in all of Richard Halley's work, through all the years of his long struggle, to the day, in his middle-age, when fame struck him suddenly and knocked him out. This – she thought, listening to the symphony – had been the goal of his struggle. ...when Richard Halley wrote this, he...She sat up straight. When did Richard Halley write this? (184.108.40.206)
It's significant that Halley wrote his Fifth Concerto, which Dagny hears for the first time here, after arriving in Atlantis. In a way, Halley had to be freed from the world of the looters before he could reach his full artistic potential. We get various mentions of contrasts between Halley's rebellious Fourth Concerto (written in the real world) and his triumphant Fifth Concerto, written in Atlantis.
Halley is also the first mystery we encounter in the novel. As we see in the above passage, his disappearance remains highly mysterious, and his Fifth Concerto is also a mysterious part of the strike that Dagny spends the first two volumes tracking down.
So actually meeting Halley is a bit of a shock for us, as it is for Dagny. Since Dagny is his number-one fan, Halley gives her a private concert and explains his view of art, which fits into Galt's value system, where all work is work "of the mind." Halley knocks down distinctions between business and art and emphasizes the importance of values, both in writing his music and in the enjoyment it produces.
"But I mean it," said Richard Halley, smiling. "I'm a businessman and I never do anything without payment. You've paid me. Do you see why I wanted to play for you tonight?. . . I don't mean your enjoyment, I don't mean your emotions – emotions be damned! – I mean your understanding, and the fact that your enjoyment was of the same nature as mine, that it came from the same source: from your intelligence, from the conscious judgment of a mind able to judge my work by the standard of the same values that went to write it." (220.127.116.11-7)
Halley may not have been able to exist in "real" world, but he can exist in the world Atlantis is building, which is the lesson his music teaches.