Reunited 1960s pop band THE BEACH BOYS have released a teaser track of their first new single in two decades - a dreamy, five part-harmony throwback to their southern California surf sound called 'That's Why God Made the Radio.'

The song will be the first single off an album of new material on which the band has been working ahead of their 50th anniversary tour, which kicks off on Tuesday.

"It's like an accolade to the radio and what it's meant to so many people," vocalist and songwriter Mike Love said in a promotional trailer released on YouTube.

"It's our new single from our new album ... if you like harmony it's going to knock your socks off," added Al Jardine.

Original Beach Boys Jardine, Love and frontman Brian Wilson have teamed up with Bruce Johnston and David Marks for album and concert tour.

Wilson's brothers Carl and Dennis, who were part of the original 1960s California line-up died in 1983 and 1998 respectively.

The new, as yet untitled album is due for release on June 5.

In the 1960s, THE BEACH BOYS epitomized the free wheeling surf culture of southern California with hits like 'Good Vibrations' and 'California Girls'.

Now in their 60s and 70s, the reunited band kicks off a 40-city anniversary tour on Tuesday in Phoenix, Arizona and will play the New Orleans Jazz Festival and the Bonnaroo music festival, among their gigs.