Sir Paul McCartney has joined his son in the recording studio.

The ex-Beatles icon's son, James - one of his four children with late wife Linda Mccartney, along with Heather, Mary and Stella - called on his father for a helping hand while recording his second studio album.

The 35-year-old musician is hard at work on his follow-up to 2011 debut 'The Complete EP Collection' - which collected previous releases 'Available Light' and 'Close at Hand' - and his dad was only happy to lend a hand.

Paul, 70, posted a picture of the pair by a mixing desk on Twitter with the caption: ''Having fun in the studio with James on his new album.''

James also tweeted about the studio session, writing: ''In the studio with Dad having a great time working on the new album.''

The generational duo are no strangers to working with each other musically, as James contributed to two of his father's solo albums, 1997's 'Flaming Pie' and 2001's 'Driving Rain', as well as mother Linda's posthumous 1998 release, 'Wide Prairie'.

Paul - who remarried for a third time to NANCY SHEVELL in 2011 - also has nine-year-old daughter Beatrice Milly with second wife Heather Mills.