Drenge’s Undertow proves the case for the bass guitar.

In his book Our Band Could Be Your Life, music critic Michael Azzerad describes the bass guitar player as having “a key role that wasn’t obviously key.” Drenge’s second band, which started with two members (an erupting recent trend—see also: Royal Blood, Honeyblood, Slaves) started with Eoin Loveless playing guitar, and his younger brother, Rory, on the drums. Their self-titled debut album was a grungy affair, lyrically replete with stereotypical small-town frustrations (the Loveless brothers are from the Derbyshire countryside).

After relocating to Sheffield, the Loveless brothers moved in with Rob Graham, and he joined them on the bass guitar. Like so many bands before them, the addition of another member made everything flow. It’s difficult to explain in concrete terms the difference Graham makes: Drenge sounds more rounded out, with a better groove and a more melodic tone.

However, the strengths of the Loveless brothers are still evident. Eoin’s guitar parts are chiming but disquieting, and Rory is a technical drummer, making full use of fills, tight rolls, crashing cymbals, and thumping bass.

Whereas Drenge was once spiky and Nirvana-esque, only the lead single “We Can Do What We Want” employs the same frenetic energy that characterized its first album. Undertow sounds more like Black Sabbath’s Paranoid. “We Can Do What We Want” is a rebel yell with a poppy riff, but still manages to come off like Tony Iommi covering the Ramones—it’s downright irresistible.

By far the most melodic song is “The Woods,” reminding us that Drenge has never been shy of their pop roots. Indeed, their producer, Ross Orton, made his name by working on M.I.A.’s Arular and Arctic Monkeys’ AM. Undertow is an instrumental jam session that highlights Graham’s contribution, clearly defining the new groove of the band with a killer bassline.

Undertow is a cohesive album with the running theme of relationships. It was a nice change from the earlier theme of living in the backwaters of Sheffield’s music scene. The fluidity of the album is probably best exemplified by first track, “Introduction,” which flows smoothly into “Running Wild.” Undertow has the same running time as Drenge but feels much tighter.

Aside from “We Can Do What We Want,” Drenge’s biting lyrical humor isn’t in full force, which is a shame coming from the man who said in an interview that he “thought my parents were trying to ruin my life [by moving to Hope, England]—my last name is Loveless and I was living in Hope.”

Ultimately, there’s something rewarding in every song on Undertow. If Drenge was mostly uptempo with the occasional leisurely number, Undertow is the reverse; yet the ratio in both cases keeps the albums diverse and interesting. At the same time, Undertow isn’t a repetition of the first album. It’s a natural evolution that retains the same core elements that made Drenge interesting: baleful lyrics (“Your dead-eyed stare/You’re running scared”), a heavy sound, and melodic guitar tones. Graham’s bass adds to the band by coloring in the sonic sketch of Drenge, making Undertow an immensely satisfying listen in the process.