The Troubles were in full flight, and in recognition of the importance of local news and coverage, and no doubt the impending arrival of competition, BBC Radio Ulster had been launched the previous year.
It was, though, a pretty formal sort of station, having replaced Radio 4 Northern Ireland on the dial.
So, the time was ripe for a truly local service, one that would entertain as well as inform in those dark days, and on March the 16th, just ahead of St. Patrick's Day, from the County Down town of Newtownards came Downtown Radio, the 17th ILR station to go on air.
I had joined in December 75 as one of the engineering team, and the following month the journalists and presenters arrived to begin the job of creating a new style of radio.
On the opening day the newsroom was handed a gift from an unlikely quarter - Prime Minister Harold Wilson resigned, and keen as mustard, the Downtown newshounds ran a newsflash, the first station in the UK to do so.
That set the tone for a service that came to be highly regarded in the Province.
The bits in between the news were ground breaking too - the popular music of the day, in glorious FM stereo for the first time in Northern Ireland, presented by personalities who knew the area, its people, and what they wanted to hear about, all done in an informal, accessible way.
They very quickly became household names, and are known to this day - Candy Devine, Big T, Hendi, John Paul...
The regulator back then was the IBA, and in granting a monopoly commercial licence they required a range of programming to be provided, and this Downtown did with enthusiasm, with over 20 weekly specialist speech and music programmes for many years.
The big genre was Country, and its enduring popularity led to the launch of Downtown Country on DAB last year.
But back to 76 - public reaction was immediate, and by the first audience survey, Downtown had 70% of adults listening each week, and became the top ILR station in the UK.
The 80s saw expansion from the Greater Belfast area to Provincewide on FM, and in 1990 came the split and Cool FM. The 90s and first years of the new century heralded more local stations, and Downtown in now providing 3 services holds its own against them.
But after 4 decades the legacy is more than that - all of the broadcasting stations have former Downtown people with them, whether that's the BBC - Radio Ulster has changed greatly to meet the competition over the years, UTV, Citybeat now Q Radio, or U105.
So, Happy Birthday Downtown, and here's to the next 40!