Sir Paul McCartney still has a ''treasure trove'' of Beatles songs he wants to play live.

The 'Paperback Writer' musician plans to continue introducing more ''hidden gems'' from his most famous band's back catalogue into his future solo shows.

He told Rolling Stone magazine: ''What I do is, each tour or each concert we're going to do, I will go back into the catalog and think, 'Wait a minute, we could do that one,' and there are a few little hidden gems.

''I haven't actually decided which ones are which yet, but I know there's so much in there. It's like a little treasure trove, you know? It's really quite a cool feeling, because as I do the songs, I am made very aware that that period when we recorded - the 10 years the Beatles were together - was a particularly rich period for art, anyway, and for us.''

The 71-year-old star also admits he has to practice to play some of the older tracks live, because he made them so complicated when he initially wrote them.

He explained: ''We laid down the track[s] as a group, and then I put the bass on afterwards, as I often did in those days. So that gave me the opportunity to really think about the bassline and make it melodic. But, of course, if I'd have thought, 'Tomorrow you're going to have to play this live,' I don't think I'd have made it so complicated!

''[Re-learning] 'Day Tripper' was [difficult]. I thought, 'I just can't do it.' It's like patting your head and rubbing your belly at the same time. It's not that easy to do. You've got to practice up on that. I goofed it a million times in rehearsal.''