The 'Wild Love' hitmaker will support the 'Satisfaction' hitmakers - Sir Mick Jagger, Ronnie Wood, Keith Richards and Charlie Watts - on June 19 at London's Twickenham Stadium on their 'No Filter Tour', and James says he believes the key to their longevity is the fact they are all still confident about performing live and pulling off an epic show for their fans.
Appearing on UK TV show 'Lorraine' on Thursday morning (17.05.18), James said: ''I got to see them [Stones] a few years ago and I am really excited to say I am going to go and open for them again in a few weeks.
''They are still great.
''I only emphasise still, because it's been about 50 years that they've been doing it.
''You watch the show and it's all the hits and performing them just as great as they are.
''They clearly still believe they've got it and if you believe then everyone else will.''
As for rocking in their 70s, James says he's been to events into the early hours and the band - who have a combined age of 294 - have still been up partying.
He laughed: ''I've been out pretty late at stuff and they've been there.''
James will be reunited with his friend Wood - who joined the 'Hold Back The River' singer on stage for a surprise appearance at his concert at London's O2 Brixton Academy in 2015.
The 27-year-old singer/songwriter also previously opened for the 'Paint It Black' hitmakers five years ago at Hyde Park, the last time they toured the UK.
Speaking about his support slot at Twickenham Stadium, James said previously: ''I grew up listening to this band.
''I was lucky enough to be on the bill with them for their legendary Hyde Park show in 2013 and had the honour of Ronnie joining us on stage at Brixton Academy in 2015. This is a band key to my musical education, so it's such a privilege to announce I'll be opening for The Rolling Stones at Twickenham Stadium this June.''