NEWARK, N.J- A Grammy-nominated violinist who left his $4 million, 285-year-old Stradivarius in a taxi repaid the driver who returned it with a free concert at an airport taxi stand on Tuesday. Philippe Quint, 34, left his 1723 Ex-Keisewetter violin in Mohammed Khalil's taxi when returning from Newark Liberty Airport in New Jersey at 3 a.m. last week and Khalil later returned it without knowing its value, Quint said.

"I was retrieving my bags from the trunk ... and when I turned back I saw the cab already very much in the distance," Quint said, immediately realizing the violin was in the back seat of the car.

After frantically reporting the loss to the taxi commission, reviewing photos of licensed taxi drivers and informing police, Quint went back to the taxi stand hoping the driver would reappear.

"It was only five or six hours from the time when it left to the time that I got it but it felt like six years of my life," Quint said.

Quint gave Khalil and his colleagues a 30-minute recital on Tuesday - although using a less valuable violin. Quint said the Stradivarius - the name for instruments made by famed Italian Antonio Stradivari - was appraised at $4 million in part because it was one of only three Ex-Keisewetter violins to exist. He has it on loan from two U.S. philanthropists.

Stradivari's instruments are praised for their sound, which projects clearly with rich tones, and are considered easy to play as they are highly responsive to a musician's touch. He made about 1,100 in his lifetime, most of them violins, and about 650 survive today.

When Quint next performs on the "Strad" in New York on Sept. 23, he will provide tickets for Khalil and his family.