IT is a vast treasure trove of the history of the arts in Glasgow over the last four decades.

Grainy footage of a performance in Glasgow by Allen Ginsberg, one of the leading figures of the Beat Generation, rare video from the 1970s of young black American minimalist composer Julius Eastman, a recording of Ivor Cutler's Life in a Scotch Sitting Room and film of South African anti-apartheid musician Lewis Mahalo are just some of the items uncovered in a trawl through the archive of Glasgow's legendary Third Eye Centre.

As the Sauchiehall Street venue, that became the CCA in 1992, marks its 40th birthday today, there is no better time to take stock of highlights over the years, and piece together the history of the arts centre set up by radical poet, playwright and musician Tom McGrath.

"When the Third Eye was here in the 1970s there was nothing like that in the city. They were all really young and started working - 40 years later and no-one has archived it or can remember what they did," said CCA director Francis McKee.

"And nobody is here who did it originally. It's going back and trying to make sense of that and then using it to help us. That has reconnected us to that early spirit of the Third Eye, and that has been helpful in regenerating the building.

"Now a lot of intern students are working on the archive and that gets us constantly talking about the organisation and reminds us to keep that as a goal and not to forget why you're here."

McKee and his team are keen to hear from anyone who was an artist, performer or even audience member in the early years who can share their memories.

Over the years some of the names to pass through the doors of the organisation range from Billy Connolly and John Byrne to regular Alasdair Gray, who launched his landmark novel Lanark there.

Now, 40 years on, McGrath's hippy ideal isn't forgotten as the CCA's open doors policy welcomes artists, offering them space to work, exhibit or perform.

It recently won the prize for Best Cultural Venue at the Glasgow Awards, recognition that the CCA is as much loved by arts-goers as makers. The attendance figures say it all. In 2014-15, more than 42,000 people attended 802 events.

With 43 staff, including full-time, part-time and freelance across administration, programming, curatorial, events, development, communications, technical, install, front of house and cleaning, the CCA is an example in these recessionary times of a success story.

Now funded by Creative Scotland as a hub, it runs a core programme of exhibitions and events as well as hosting the work of artists from at home and abroad.

A total of 80 per cent of activity in the CCA now is by other people, underwriting artist projects that otherwise might not see the light of day. And four cities in South Africa, including Johannesburg and Cape Town, are keen to follow the CCA example.