The great thing about a Chris Belleau record is that you never know what the Baton Rouge roots musician is going to do next, but guaranteed, an indigenous identity will be present. Belleau’s fourth release focuses on blues and jazz, the latter being a genre that he has the most performance experience in as a trombonist. As usual, he surrounds himself with good studio musicians such as saxman Jon Smith of White Trash fame and keyboardist/guitarist/producer Nelson Blanchard.

His harp lines have respectable burning power, as evidenced by the Kenny Neal–inspired “Blues Is on the Rise.” While “Hold the One Who Cares” is obviously steeped in swamp pop, it’s also bluesier than most.

Lyrics for three songs were written by former Muscle Shoals FAME Studios lyricist Billy E. Henderson, while Belleau crafted the melodies. The similarly themed “The Healer” and “The Treater” are bluesy swamp rockers while the title track is interpreted as a sultry jazz ballad. Of the two jazz instrumentals, Belleau’s “Bienville Blues” is a swanky swing shuffle while Mingus’ “Goodbye Pork Pie Hat” proves that Belleau, Smith and keyboardist Mike Esneault have the chops to tackle the heavier stuff.

Though there are millions of renditions of “When You’re Smiling,” Belleau’s euphoric version is distinct, given Brian Brignac’s second line rhythms and Esneault’s rollicking ivories.

Swamp Fever is a rare breed given its sonic diversity, especially considering a lot is packed into this 47-minute / 8-song affair.