On Thursday, 27-year-old Artem Timofeyev was arrested by police and charged with theft, trafficking in stolen goods, exposing counterfeit mark and fraud over $5,000.
Police allege that Timofeyev walked into the hospital, loaded the instrument on a dolly and then used a service elevator to take it down to a red-and-white cargo van waiting in the loading zone.
Two other people were involved in the theft, which occurred on July 14.
Todd Milne, the head of hospital security, said employees asked the men what they were doing with the piano. But when they explained they needed to take the piano for some musical servicing, staff left the men alone to whisk the instrument away.
Milne said the hospital didn't realize the prized instrument was gone until four days later, just before one of the scheduled live music shows.
"We found it very strange," Milne said.
A little over a week after the theft, police recovered the piano. It turned out the Boston Steinway piano was sold to a local business.
A warrant for Timofeyev's arrest was put out in July. He was due to appear in court on Tuesday morning.