Chris Squire - bassist and sole constant in prog-rockers Yes - reflects on the group's longevity using the only reference point he had when the group formed.
"When Yes started in '68 that was a year prior to the Beatles breaking up. Their visible career was really just '63 to '69 and when I started Yes I thought it would be amazing if we could have a five or six-year career. And here we are in year 46 or something," he laughs.
"We never thought that was possible. It was a young man's game and not something for life. But I was wrong. It's a testament to the [prog-rock] genre that it has lasted.
"Also - and I know this from touring the last couple of years - that, apart from fans who came to the band in the 80s which was a successful period with the 90125 album and are still in the audience, a lot of younger people come to shows."
Although it's the senior musician's cliche about attracting younger audiences, it's true for Yes. In the August issue of Britain's Prog magazine their '72 album Close to the Edge was voted the top prog album of all time by readers and musicians. Fragile from '71 came in at number 10.
Of the 100 greatest prog albums Yes had seven, one more than Genesis, Pink Floyd and Marillion in a list which included contemporary proggers like Dream Theatre, Porcupine Tree, Opeth and Haken.
Business is brisk for Yes who released their 21st studio album Heaven and Earth earlier this year, the first with singer/writer Jon Davison.
They also toured in Canada, did the annual prog-rock Caribbean cruise, had dates across Britain and Europe and then an American summer tour.
And for their return visit - they were here in early 2012 - they will play Fragile and Close to the Edge in their entirety, and close with material from Heaven and Earth and some hits.
"By now we should know how to play those [albums]. They've been on-and-off part of the repertoire over the years.
"Especially And You and I [the 10-minute piece on Close to the Edge] which has been more a staple than Close to the Edge itself or Siberian Khatru. They've all been in different sets at different times so are in our DNA."
But having played these songs for decades can they still find something in them?
"There's always the joy of the performance and fine-tuning new interpretations. Over the years we've all grown as musicians, so obviously there is a lot of subtlety that wasn't there in the first place.
"But Yes has been flexible. In the 80s with [guitarist] Trevor Rabin we made a diversion into regular hard rock to an extent, and the 90125 album with [the hit single] Owner of a Lonely Heart was a slightly different Yes to that of the 70s.
"Of course every time there's a new member they bring in ideas and the music subtly changes again.
"We've been playing a couple from Heaven and Earth and I'm surprised how well they are received.
"I saw The Who in London a few years back when they had a new album out and there was a distinct lack of interest from the audience when they played new songs.
"In contrast, our fans are enjoying the songs from the new album."
Who: Chris Squire, founding member of prog-rock legends Yes
What: Yes playing their classic albums Fragile and Close to the Edge
When: Aotea Centre, tonight.