Boulder Acoustic Society

Boulder Acoustic Society members tend to be characterized as makers of hippie music. By those standards, then, Caged Bird qualifies as first-rate hippie music — a batch of songs that are often deeper, darker and more intriguing than haters of the style typically expect.

The playing of multi-instrumentalists Kailin Young, Brad Jones, Scott Aller, Aaron Keim and Scott McCormick doesn’t meander in search of inspiration. It’s tight and pungent on the plaintive “Walk” and an unexpectedly sinister version of the Dylan chestnut “Maggie’s Farm.” And while material such as “Sparrow Weeps” doesn’t exactly revolutionize the subgenre, other tunes push at its boundaries, including “In the Year of Our Lord,” featuring a muted brass section, and “No Matter What I Do,” which finds common ground between bluegrass and rockabilly, with a little yodeling thrown in for good measure.

That’s putting the “hip” in hippie.