At the intersection of bluegrass instrumentation and folk earnestness, this quartet from Raleigh has found a tidy niche for itself. With the exception of an uptempo, banjo-driven instrumental (“Bull City Strut”), this music sounds like it would be more at home within the close confines of a coffeehouse (from vintage Greenwich Village to contemporary Starbucks) than in the open air of a bluegrass fest. As befits the album’s title, Autumn (out September 2 on Yep Roc) has a reflective maturity of a veteran band that has passed through its spring and summer, and has settled into a somber spirit to match the mid-tempo music. With much gravitas, frontman Dave Wilson shows that it’s possible to sing “You are my spark” (in the opening “You Are My Light”) without a flicker of spark, and then segue into a song titled “Bon Ton Roulet,” that sounds more like the hangover aftermath of too much good times. Other material offers an elegy for a beloved dog (“Jackie Boy”), pays a visit to a roadside graveyard (“All That’s Left”) and warns of a mysterious, soul-stealing midnight rambler (“Dark Rider”). Harmonica and piano occasionally punctuate the acoustic arrangements, and the most distinctively memorable music here (“Moving Pictures of My Mind”) sounds more like a chamber ensemble than a bluegrass band. The world weighs heavy on the shoulders of songs that suggest the approach of winter’s chill.