The five-piece, fronted by singer Matiu Walters, spent two full days with Pharrell, creating two songs together. Walters shares vocals with Pharrell on the tracks, but they remain half-finished and aren't sure when, or if, they'll be released.
Either way, guitarist Ji Fraser says the session was a learning experience for the group.
"It's awesome being in that environment because you immediately step up your game. It was such a cool environment: Common was there, Pusha T walked in, The Weeknd was walking around."
It was another highlight to add to the collection. Six60 also released their second self-titled album in February, hitting No. 1, signed a global management deal with Capitol Records, and scooped the People's Choice trophy at the recent Music Awards.
They'll finish the year by kicking off a summer tour in Butlers Reef that rolls into the New Year, finishing up with a sold-out show at Auckland's Villa Maria Winery on January 16.
After selling out Auckland's Vector Arena in May, Villa Maria will be their biggest headlining show in New Zealand yet, and they can't wait to get there.
"That's what you want to do - you want to play to as many people as possible," says Mac. "The new album needs to be played to tens of thousands of people. This is where it's supposed to be."
"That amount of people singing your song is pretty damn cool," adds Ji.
Who: Six60
Where and when: Butlers Reef, Oakura, December 26; Riwaka Hotel, December 28; Cathedral Square, Christchurch, December 31; Toll Stadium, Whangarei, January 2; Coroglen Tavern, Whitianga, January 4; McEwan Park, Lower Hutt, January 6; Brewers Field, Mt Maunganui, January 9; Villa Maria Winery, Auckland, January 16.