Bicyclists have towed any number of things behind their bikes -- children, pets, camping gear.

Carl Hildebrandt, 56, of Squirrel Hill added one more item to that list.

The pediatrician, professional musician and veteran cyclist towed an upright bass 303 miles across Michigan as a member of the Joybox Express Quartet, a group of professional musicians who donated their time, talents and legs to raise money for children's charities.

Mark Braun of Ann Arbor, also known as "Mister B," led the group. He pedaled a blue Mark Nobilette custom-designed tricycle with a plywood platform that held a piano, an instrument also known as a "joybox."

Additional pedal power was provided by Pete Siers, a drummer, and Brian Delaney, a guitarist whose equipment included a solar-powered amplifier. The front forks of their bicycles were attached to the back of the tricycle frame.

Total weight, including the instruments, a cooler, gear and clothing, was more than 500 pounds.

"They hit 37 miles an hour going downhill, but they were seriously using their granny gear to climb out of river valleys," Hildebrandt said.

Braun, a blues and boogie-woogie pianist who has performed throughout the U.S., Europe and the Americas, invited Hildebrandt, Siers and Delaney to join him in playing at venues large and small.

They also did some impromptu performances, including one after they got directions from a passing motorist and his family on a country road.

"We astonished them and their children by pulling off our cover and playing them a tune," Braun wrote on his blog. "Did the same for some kids at our hotel. That's one of the best parts of all this -- surprising people at odd locations when they would never expect it. But then, where would you expect a piano bike?"

They traversed Michigan from west to east. They began July 2 in Saugatuck and ended July 14 in Detroit.

"We played just about every day," Hildebrandt said.

One of the highlights was the Top of the Park Summer Festival in Ann Arbor, where the mayor designated the day as Joybox Express Day.

They averaged about 30 miles a day but rode 54 miles in 96-degree temperatures on their longest day.

The piano bike, dubbed the "Mothership," broke down the second day about a half mile from a gig in Holland, Mich. They were scheduled to perform in 90 minutes. It was time for some "road magic."

A woman drove up, recognized them and called her husband, a bike mechanic. His bike repair kit was in her car, and it contained a master link needed to repair the chain of the Mothership.

"To play with these guys was a real privilege," said Hildebrandt, who was a Category 2 road rider with the Wolverine Sports Club in his early 20s. He comes from a musical family. His father Mark is a cellist; mother Jennie Weller is a pianist; brother Jay is a professional drummer; and late paternal grandfather, Theofil, was a church organist.

Hildebrandt, who played with Billy Price from 1991-95, can be found most Wednesday evenings at a small industrial building in East Carnegie that serves as the business and home of Ron Wilson, a guitarist who owns and operates the Answer Group, a computer-related business.

They're often joined by drummer Vince Taglieri and saxophonists Lou Stellute and Don Aliquo Sr. The venue seats about 60.

Hildebrandt said his travels with the quartet were "an unqualified success. We raised thousands of dollars for a number of charities. I hope to be able to do it again."

Information: www.joyboxexpress.com, joyboxexpress.blogspot.com/ and www.youtube.com/watch?v=xhrzMCFd4Ws.

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