Maroon 5's next album will be ''darker''.

The 'Payphone' hitmakers are already planning their fifth record after the success of 2012's platinum-selling 'Overexposed' and hinted they may be exploring a harder, less poppy sound.

Guitarist James Valentine told Billboard.com: ''It kind of keeps changing. There was a first batch of songs that seemed like they were darker and maybe a little more organic-sounding, but now there's some other songs that ... it's hard to describe, and I think we're going to really find out where it's going in the next few months.''

While the musician refused to give too much creative information away, he admitted the band had made an ''amazing'' start on the tracklist.

James explained: ''It's still sort of in the early stages. We definitely have a couple of amazing songs that will be on the record. I think we just really like making music now, and I think we're more prolific than ever.

''But at the same time it's going to be awhile before the record comes out, so maybe some of the stuff we're doing now will fall by the wayside by the time we actually put it out. But we've got some great stuff started, and we're all very excited.''

He also revealed keyboardist Jesse Carmichael would only rejoin the Adam Levine-fronted group after his sabbatical - during which he was replaced by PJ Morton - once their current tour is over, and he can't wait to have the whole gang back together.

James explained: ''We figured that was the most simple way to do it. It's an unusual sort of thing, I guess, but there's no clear rules as to how to do that.

''I think it's completely understandable he wanted to get off the carousel for a second, but I do get the impression that he's eager to get back.''