Sir Paul McCartney and his band are planning to release an album of cuts from their improvised soundchecks.

The Beatles legend teased it's a ''treasure trove'' of unheard material they've been keeping recordings of over the years.

In an interview for his website paulmccartney.com, the 77-year-old rocker was asked if they still ad-lib at soundcheck, and he replied: ''Yeah, we do!

''We've got millions of them!

''And fortunately, there's a guy called Jamie, who logs them.

''It's a little treasure trove!

''And one day we will have to put together an album or seething, with a selection of these songs the that we've gathered.''

Meanwhile, McCartney has just announced he's working on a stage adaptation of 'It's A Wonderful Life'.

The 'Let it Be' hitmaker is in the process of turning the 1946 film - which starred the likes of James Stewart and Donna Reed - into a musical production after teaming up with Bill Kenwright, who will produce the project.

He said: ''Like many of these things this all started with an email. Bill had asked if it was something I might be up for.

''Writing a musical is not something that had ever really appealed to me but Bill and I met up with Lee Hall and had a chat and I found myself thinking this could be interesting and fun.''

The film plot tells the story of George Bailey (James), who is saved by his guardian angel Clarence Odbody (Henry Travers) after being on the brink of taking his own life.

He added: '''It's a Wonderful Life' is a universal story we can all relate to.''

The music icon - who released his 17th solo album 'Egypt Station' in September - is said to be writing the music for the production, and he has joined forces with Lee Hall to pen the lyrics.