Kelly Clarkson's unambiguous orchestral balladry hasn't been heard in its full glory since 2011's Stronger – save for misguided 2013 Christmas album Wrapped in Red. Four years after her last full studio album, the American Idol star has set the tone for her 2015 with Piece by Piece.

Throughout what has been a whirlwind career and rise to fame, Clarkson's music has primarily revolved around themes of heartbreak, survival, struggle and self-empowerment, all thrown together under the banners of country and pop. Staying true to her origins, Clarkson covers the same lyrical themes on her latest LP, but shows signs of evolution, with Piece by Piece taking strong eighties inspirations as well as sprinkling it all with a hint of electro-pop.

With a catchy bubblegum chorus and a cheery Clarkson crooning about an exhilarating new love, 'Heartbeat Song' opens the album, which, as a whole, shows Clarkson's voice to be much more versatile – something that is perhaps most evident on 'Invincible'. Co-written by Sia Fuhrler, the track is a slow-building power ballad that mixes the worlds of pop and electronic music to chart-friendly effect and feels like a continuation by previous hit single, 'What Doesn't Kill You (Stronger)'.

Covering none-other-than German rock band, Tokio Hotel, Clarkson delivers an r&b-adorned duet of 'Run Run Run' with John Legend; a tune dripping with despair that gives the album more emotional depth – and, of course, the vocals of Mr Legend. But for every emotional exploration, there's an equally hollow song to go with it; tracks like 'Dance with Me' sees Clarkson lean the way of contemporaries such as Katy Perry with a disco-pop number that sees her sing, "And when the music starts and the lights go down we will all be found."

It's this type of modern chart pop that sways the album into mimicry; 'Take you High' draws heavily on the use of electronic vocal tampering, resulting in Clarkson's vocals being void of any of its distinctiveness.

This is the struggle that 'Piece by Piece' embodies; it feels like Clarkson is trying too hard to make a statement – what that statement might be isn't immediately clear, but it's almost certainly motivated by the need to stay relevant. The lyrics go from being emotionally draining and gritty to fun and bubbly, and while it showcases a flexibility and adaptability that we've not seen often, Clarkson shines brightest when she uses her strengths – namely, her voice. While she delivers the more en vogue pop sounds well, she is at her best when her voice leads – something that doesn't always happen on what is a largely digestible album.