The news comes as the acclaimed band completes work (with Beste on bass) on their fourth studio album in Nashville at LCS Studios with an expected release this summer.

Beste was recruited by the band last August as a fill-in bass player for their Norwegian festival dates and US tour after original bassist Robin Everhart left the band.

Frontman Jay Buchanan had this to say, "Personnel change in a band this tight can be a very worried thing. Suddenly, you have to reprogram yourself from hearing and doing things in a familiar way in order to move forward, sink into and appreciate the new.

"That 'new' is Dave Beste and he's been completely killing it. A close friend of mine for many years, Beste committed wholeheartedly to helping us out when we were in a tight spot and it didn't take long to see that the fit couldn't be more natural. Also, I can't wait for people to hear his playing on this new record because he delivered in spades. So, now it is official. Bonafide. Dave Beste is a Rival Son."