The Steep Canyon Rangers have spent much of their career walking a fine line between traditional bluegrass and acoustic music with a strong contemporary pop and country influence, and they've blurred the lines between the two sides of their musical personality more than ever before on 2015's Radio.

One of the key differences on Radio is the addition of a sixth Ranger, percussionist Mike Ashworth, and even though his kit primarily consists of just a box played with brushes, his steady pulse subtly but clearly points to the melodic hooks in numbers like "Simple Is Me," "Blow Me Away," "Long Summer," and the title tune, and without having to plug into an amp, the Rangers set themselves apart from bluegrass acts who prefer to pretend it's still the early '50s.

At the same time, these musicians are remarkably skilled, both as individuals and as an ensemble, and when they do dig into their bluegrass roots, they do so with a clear love and respect for the form, and with "Blue Velvet Rain," "Looking Glass," and "When the Well Runs Dry" they show just how fresh they can sound while working within a tried-and-true framework.

It's a thrill to hear a band this good playing together, and Ashworth, Mike Guggino (mandolin), Charles R.

Humphrey III (bass), Woody Platt (guitar), Nicky Sanders (fiddle), and Graham Sharp (banjo) are as gifted as any young band in bluegrass, with each member earning his stripes when stepping up for a solo, and coming together with outstanding ensemble work and spot-on harmonies.

Produced by Jerry Douglas, who captures the group's musical interplay beautifully and contributes some fine Dobro work as well, Radio is an outstanding album from one of the most exciting new bands in bluegrass, and if you know them best for their work with a certain talented banjo-playing comedian and actor, you owe it to yourself to find out how much they can do on their own.