When Derek Paravacini, 32, played his concerto in London's Queen Elizabeth Hall Wednesday night, he knew the piece by heart -- and all the parts for each instrument in the orchestra, about 45 in all.
But Paravacini has never looked at a single piece of music. He learned the concerto after hearing a computer play it a few times.
"There must be 10,000 notes, and he's got it all in his head," said Adam Ockelford, a music professor and Paravacini's mentor. "It's amazing."
Paravacini is severely autistic and has been blind since birth. He is also a musical savant. He can play just about any song, from Bach to Britney Spears, after hearing it just once.
The concerto Paravacini played Wednesday night was written specifically for him by Matthew King, who met Paravacini a few years ago and was inspired by his abilities.
"He's not like any other musician I've ever worked with," King said. "I think music is almost like a substitute for language. He's spent his whole life communicating through music."
Paravacini's talents showed up early. At age 2, he began teaching himself to play the piano, listening to jazz tunes and old standards and playing them back by ear. When Paravacini was 5 years old, he met Ockelford, then a music teacher at Linden Lodge School for the Blind in London.
"He sat me down and started playing for me," said Ockelford, now a music professor at Roe Hampton University in London.
Ockelford was impressed, and more than 25 years later, he and Paravacini still work together. Paravacini has performed in concerts all over the world since age 9.
"It's not uncommon for autistic children to be musical," Ockelford said. "What's unusual is Derek's taken it to such extremes."
Savants have fascinated scientists and society for hundreds of years. Their abilities in music, art, math and other areas contrast starkly with developmental disabilities like autism, which cause severe impairment in language, communication and learning.
Dr. Darold Treffert has studied savants for many years. He is a psychiatrist in Wisconsin and was a consultant for the movie "Rain Man," in which Dustin Hoffman portrayed a savant. In his research, Treffert has observed many savants like Paravacini who are blind, have a developmental disability, and are considered musical geniuses. Treffert said scientists can't explain how those qualities are connected.
"We're trying to understand where that triad comes from," he said. "We're also still trying to unravel what savant syndrome means for all of us in terms of human potential."
Treffert met Paravacini when he was 8 years old. He said there are probably fewer than 100 people in the world with Paravacini's abilities.
"They instinctively and innately know the rules of music, which most people spend a lifetime trying to learn," he said.
Treffert said those rules of music are what draws savants to master it. Music is often repetitive and has a specific structure that savants master easily. Even the design of the instrument can make a difference. Treffert said that most savants are drawn to the piano.
"I think it has to do with the symmetry of the keys," he said.
Many scientists have noted that music, math and other skills that come easily to savants are associated with the right side of the brain. Some autism research has linked that disorder to dysfunction in the left side of the brain, which also is associated with the control of language and communication.
Even autistic people without savant capabilities often show a particular affinity for music.
Dr. Leo Kanner, the first scientist to study and document cases of autism in the 1940s, noted that many of his patients were drawn to music.
Lori Warner, a psychologist and the director of the HOPE Center at Beaumont Hospital in Michigan, said music opens a pathway to emotion and communication that is usually closed for people with autism.
"It's a way to connect without the use of words, but still get that emotion, that feeling," she said. "It's especially appealing if your ability to use language is somewhat limited."
Treffert said the more savants like Paravacini practice their abilities, the more some of them can improve in other areas of their lives that are typically impaired by autism. In the 24 years he's known Paravacini, Treffert said he's been impressed by how greatly his independence and his ability to socialize have improved.
"Not only that, but his musical abilities have come far as well," Treffert said. "One of the things that Derek does better than other savants is stylizing or improvising music."
Paravacini's improvisational skills were what first impressed King, the composer who wrote Paravacini's concerto. He said he wrote the music to reflect Paravacini's ability to improvise and to honor Paravacini's favorite composer, George Gershwin.
King said he thinks Paravacini's improvisation can make his performances even more interesting.
"The way he plays it is different every time, he embellishes some things of his own," King said. "He can go slightly down the wrong tube sometimes, but that's part of the excitement."
Ockelford, Paravacini's mentor, said life for Paravacini would vastly different if he couldn't express himself through his music.
"Music is Derek, Derek is music," Ockelford said. "It's everything he thinks about, it's how he communicates, everything is related to music. It's impossible to imagine Derek without music."