Johnnyswim's dynamic, broadly emotional pop music is built around the voices of Amanda Sudano and Abner Ramirez, and on their first full-length album, Diamonds, they prove that their vocals are strong enough to support their creative ambitions.

Sudano is the daughter of disco icon Donna Summer, and if she's a different kind of singer than her mother -- breathier and with a rootsy feel that makes room for soul and country inflections -- she's just about as strong and she communicates these songs of hard lives and difficult relationships with both passion and skill.

Ramirez is an excellent vocal foil for Sudano and more than capable when he takes the lead, and he also handles many of the instrumental chores on this set, helping build the musical backdrops that turn from spare to immense at a moment's notice.

Sudano and Ramirez had a hand in writing the material on Diamonds (the couple's musical and personal relationship was launched when Sudano took a songwriting course led by Ramirez), and they're able to give the tunes a personal emotional force that makes them all the more compelling.

If Diamonds has a flaw, it's that the angst that dominates many of the songs doesn't leave much for room for the moments of joy that come too few and far between in numbers like the rousing "Home" and the sweetly subdued "Paris in June." But there's no arguing Johnnyswim are very good at what they do, and with Diamonds they've made the sort of well-crafted album likely to win them the larger audience they want and deserve.