★★★★☆

Following her immense success with the indie-rock band the Yeah Yeah Yeahs, lead singer Karen O is branching out in a solo career with her debut album, “Crush Songs.” The South Korean-born American singer, known for her quirky style and unusual vocals, has created an album that perfectly showcases her haunting voice with beautiful lyrics.

As part of the album’s artwork, Karen O writes, “When I was 27 I crushed a lot … I wasn’t sure I’d ever fall in love again. These songs were written and recorded in private around this time.”

Most of the songs on the album are unusually short, acting as little reflections on different aspects of falling in love. It’s as if she’s sharing with her fans a rough draft of the kind of music she wants to produce, with subjects far more personal than the work with her previous band. The topic of “Crush Songs” is a surprising choice for Karen O, who is best known for the darker, hand-banging hits like “Gold Lion” and “Heads Will Roll.” In fact, the album is an unexpectedly and intentionally modest work for a debut, piecing together tracks that sound more like demos in an impressively successful way.

The album opens with “Ooo,” a slow, dreamy track reminiscent of gramophone-era music. O’s unique vocals combined with the grainy sound of the vinyl imitation makes the song addictive listening.

While the album title may suggest that O tried to produce a collection of sappy love songs, her raw, punky singing style nevertheless leaks through. A number of tracks reveal her characteristic rebelliousness, as she snaps that “Love’s soft, love’s a f—— b—-” in “Rapt,” interrupting the more dreamy suggestions in the album to remind us that she is still a New York rebel at heart.

As you work your way through the album, you feel more as if you are sitting with O in her room as she strums away on her guitar, crafting these short songs about how it feels to have a crush and fall in love. Many of the songs, in contrast to some of the hits of her punky past, seem surprisingly innocent and simple. At the start of “Indian Summer,” O dreamily muses about how “I like you best,” and many of the tracks adopt these similarly stripped-back, clear lyrics, creating a surprisingly intimate sound.

The decision to experiment with acoustic pieces is a surprising, yet welcome choice following her increasingly electronic and punky work with the Yeah Yeah Yeahs — “Heads Will Roll” became a club DJ favorite, remixed into a number of dance floor hits.

In “NYC,” which is less than a minute long, O almost whispers the lyrics as she muses along with a strumming guitar how “I left my baby in New York City” with a lullaby-like rhythm. It’s a far cry from her days spent head banging with her black bob while screaming into a microphone covered in bright feathers.

One of the standout tracks has to be “Body.” While it sticks to the album’s characteristic low-key production, O’s vocals suddenly change to pick up her more powerful style. This commanding voice combines with almost whimsical wails and shrieks in a frenzied musical interlude to create a tangle of sounds that is both confusing and enchanting. It’s a combination of vibrant romance and gritty indie rock that only O could pull off.

At first, this album engages listeners with its unusual production and even more unusual weaving together of tracks that sound borderline incomplete. However, this inability to commit to and expand these songs actually inhibits it from reaching its full potential. None of the tracks seem to reach a climactic point or build to anything substantial. While there is undoubtedly something beautiful about being taken along with O on her musings about love and relationships, her noncommittal attitude on the album can become frustrating. Her demo-like style often makes it seem like she’s holding back and consequently gives the album an incomplete feeling.

This scrapbook album studies what it means to have a crush and how to deal with the more bitter parts of love. It is an impressively unusual debut, and in that sense perfectly fits with what one might expect of the quirky Karen O. The wandering musings may lose you halfway through, but her incredibly unique singing style will nonetheless have you coming back for more.