Beginning his second effort that fall, West would invest two million dollars and take over a year to craft his second album. West was significantly inspired by Roseland NYC Live, a 1998 live album by English trip hop group Portishead, produced with the New York Philharmonic Orchestra. Early in his career, the live album had inspired him to incorporate string arrangements into his hip-hop production. Though West had not been able to afford many live instruments around the time of his debut album, the money from his commercial success enabled him to hire a string orchestra for his second album Late Registration. West collaborated with American film score composer Jon Brion, who served as the album's co-executive producer for several tracks. Although Brion had no prior experience in creating hip-hop records, he and West found that they could productively work together after their first afternoon in the studio where they discovered that neither confined his musical knowledge and vision to one specific genre. Late Registration sold over 2.3 million units in the United States alone by the end of 2005 and was considered by industry observers as the only successful major album release of the fall season, which had been plagued by steadily declining CD sales.

Answer this question, if possible (if impossible, reply "unanswerable"): What kind of ensemble did Kanye hire to work on his second album?
string orchestra