Michael Franti & Spearhead owe the breakthrough of their 16-year career to their infectiously happy 2008 radio hit “Say Hey (I Love You),” and they certainly plan on sticking with the same chipper message on their new album, Sound of Sunshine.

This upbeat title, however, has dark roots. The life-affirming album was written when Franti almost died from an appendix rupture. On his assumed deathbed, the composer poured out 11 songs about love, friendship and the beauty of life. Throw in some recording sessions in Jamaica and legendary producer Sly & Robbie — who worked with Bob Dylan, Santana and No Doubt — and The Sound of Sunshine feels predictably breezy, but not without substance.

Underneath the surface-level cheer are complex sounds that weave through the pulsating grooves of reggae and hip hop with the catchy hooks of  pop-rock. The album boasts variety, as songs range from the U2-esqe arena anthem “I’ll Be Waiting” to the ’70s hard rock homage “The Thing That Helps Me Get Through.” The first single, “Shake It,” which also happens to be one of the album’s best tracks, is a reggae dancehall groove that features the impeccable flow of Jamacian reggae singer Lady Saw.

The lack of a cohesive sound sometimes detracts from the album’s identity, but Franti’s distinctively soulful voice — whether he is throwing down verses or lightly humming melodies — is easily recognizable and helps to unify the album.

It’s hard not to enjoy Franti’s complex, uplifting music. Even if the sonic changes are often distracting and the persistent gaiety unoriginal, the tunes have an undeniable appeal; the biggest ice-queen could be thawed by the burn of Franti’s honest and soulful message.  It’s just too damn happy to ignore.