By night, he's the bass player in pub rock-country-folk outfit The A-Street Band.
Featuring a line-up of work mates from the Alice Street Medical Centre in Atherton, far north Queensland, the band has even released a covers album aptly called Not The Day Job.
"Some of our registrars came through and joined ... and now we've got a couple of patients as well," Dr McLellan told AAP.
The veteran doctor is the archetype of a rural generalist, a career luring more young medicos to the bush for its variety, challenge and adventure.
Training places at the Australian College of Rural and Remote Medicine have been oversubscribed for three consecutive years, a hopeful milestone for boosting the medical workforce outside the cities.
Rural generalists, GPs who have additional advanced training in areas like obstetrics, were listed as specialists under national changes in 2025.
That was the result of a years-long push for greater recognition of the highly-skilled doctors who live and work in the bush, or support remote communities through programs like the Royal Flying Doctor Service.
Dr McLellan's four-decade career was honoured with a Rural Doctors Association of Queensland life membership in late June.
He found himself in Atherton as a young doctor in the 1980s, initially intending to stay for a year while saving up for a sailing trip.
But he quickly discovered the fascinating work in a rural hospital.
As one of three doctors in a 90-bed facility, he worked long hours delivering babies and offering "cradle-to-grave" care for the community.
The small team were early adopters of clot-busting treatment for heart attacks.
"It was just revolutionary," Dr McLellan told AAP.
"You could dissolve the clots in the heart and see people almost coming back to life before your eyes."
When the hours became too much, he went into private practice as a GP while assisting with obstetrics at the hospital.
Dr McLellan never did take that sailing trip, marrying nurse Michelle and raising their two children in Atherton.
In 2015, he was one of many doctors to set-up a mini intensive care burns unit after a car crash caused a catastrophic gas explosion in nearby Ravenshoe.
"There were 16 or 17 desperately ill patients," Dr McLellan recalled.
"We had to keep those people stable until they could be evacuated.
"That's the nature of rural generalism - you may well be working in general practice but you still do emergency medicine depending on the day."
Dr McLellan is hopeful about the next generation of rural doctors, who he sees doing previously "impossible" things such as re-opening birthing units in remote towns.
Training doctors in rural areas is a proven way to keep them, with rock band gigs just one of the many unexpected joys, Dr McLellan said.
"I love living where I do, it's a beautiful place to live.
"I've got patients I've been looking after since 1985, I delivered them and their children.
"Those things really are very rewarding."
