Bill Sheehan enjoys a lively gathering around music as much as anyone. Bonnaroo, Lollapalooza, Great Blue Heron – you name the festival, and the retired teacher is a big fan.

So when friends began exploring ways to assist Sheehan’s recovery from a devastating brain injury suffered in April, an outdoor music festival in his honor seemed like the perfect fundraiser.

Thus was born the Sheehan Sunshine Music Festival, also known as Billapalooza, scheduled for next Sunday at the Wings Flights of Hope Pavilion on California Road in Orchard Park.

Sheehan, 61, taught science at Lake Shore High School for more than 30 years until his retirement in 2007. Several of his students from years ago will be among those performing on his behalf.

Sheehan was struck by a pickup truck the night of April 1 in a horrific accident on Route 5, near Milestrip Road, in the Town of Hamburg. He and his wife, Marcy, were westbound on the way to their Hamburg home when their Chevy Blazer slid on black ice into a barrier. Another car slid and hit their vehicle a few minutes later.

No one was injured in the collisions. But then a third vehicle, a pickup truck sped into the same area.

A Hamburg police officer who had arrived on scene tried to stop the pickup truck by waving his flashlight. But the pickup didn’t slow down, and the patrolman had to jump out of the way to avoid being hit, according to an accident report.

The pickup barreled into Sheehan’s vehicle, which ended up hitting Sheehan and a friend, Michael A. Serrano, who were walking nearby. Sheehan was thrown 200 feet by the force of the collision. Both men were rushed to Erie County Medical Center with traumatic brain injuries. The pickup driver, Thomas A. Gilray Jr., an Erie County sheriff’s dispatcher, was charged with driving while intoxicated, vehicular assault and reckless endangerment.

In addition to his brain injuries, Sheehan suffered a broken neck, a broken arm, a dislocated knee and deep cuts to his ear and chin. He spent about two months in a coma at ECMC and has been in a rehabilitation program at Craig Hospital in Denver since June.

Family and friends said Sheehan has made great strides in rehabilitation, but he struggles to communicate, can’t walk, and has a condition called acquired apraxia, which limits his ability to perform everyday muscle movements and causes him to do routine tasks out of order, even when he understands what he’s being asked to do. He talks in a whisper and has amnesia that could be limiting his ability to re-learn some basic motor skills.

“He still needs 24-hour care for another two to three months,” said his daughter, Molly Sheehan. “He’s still locked up inside his brain.”

Insurance coverage for care at Craig is set to run out in August, and his family has yet to locate a rehab facility in Western New York where care can be continued. Proceeds from the festival will go into a fund to make the Sheehan’s home more accessible and provide additional therapy.

A healthy Sheehan would have been the first person to sign up for the festival, said family and friends.

“One of the first things we did in the ICU was play music for him, and he would be tapping his foot,” his daughter said.

Spearheading the festival are some of Sheehan’s closest colleagues from Lake Shore, who reached out to former students through Facebook. Within two months, they received commitments from nine bands and solo acts.

Rich Borosky, a 1997 graduate of Lake Shore and a local television producer, was more than eager to chip in with his band, Wheelhouse.

Lake Shore students were well aware of Sheehan’s affinity for music and festivals, said Borosky.

“We knew that he was a huge Grateful Dead fan, and just a music lover in general,” he said. “I think this is the perfect way to not only honor him but to raise funds for him.”

Other bands on the bill include BWT, The Stys, Cosmic Shakedown and Burned.

Continuous music will play from 2 to 8 p.m. on two stages at the fundraiser. About 60 Lake Shore faculty and alumni have agreed to work the festival. Another Lake Shore graduate designed the festival poster, tie-dyed T-shirt and buttons.

Admission to the festival is $25.