The story of Cassie Ventura is a weird one. Beloved of whatever stage name Sean Coombs was going by in those days, she released her self-titled debut album in 2006. You probably heard 'Me & U' if you were alive at the time and had ears. And since then... well, she's not done a whole lot. Officially, anyway - behind the scenes, she's been struggling to decide what her next step after Cassie's sexy-yet-sweet, smooth mid-00s R&B sound would be. 'Must Be Love', a single featuring Diddy, strayed towards the sound of early, crackly-sample hip-hop. 'Activate', the result of some aborted recording sessions, was a fuzzy, thrilling dance track that Björk likes to slip into DJ sets. Last year's botched comeback single, 'King of Hearts' was a failed attempt at a club banger. The unreleased 'Don't Go Too Slow' was a minimalistic, hot-and-heavy slow jam. She was a confused Mr Benn, trying on numerous genre suits, looking to find one that fit.

Well, it's only taken seven years, but it looks like she's found her style. Whilst Ventura and her 'people' still claim the album which (allegedly) features 'Activate', 'Slow' and '...Hearts' is on the horizon, mixtape RockaByeBaby will do in the meantime. Following a loose narrative based on 90s drug dealer drama New Jack City – copious vocal samples from which are sprinkled throughout – the tape sees the R&B ingénue of Cassie fully embody the aggressive rap persona showcased during her appearance on Nicki Minaj's stop-start single 'The Boys'.

Clearly part of the problem with Cassie finding her 'place' within (sorry for using this phrase) the urban music scene was the fickle nature of fashion - with RockaByeBaby the various producers latch onto the current trap style of massive synth lines, metallic programmed drums and rumbling bass. Guest spots come from Pusha T, doing his cocaine-rap thing on 'Take Care Of Me Baby'; Rick Ross trying not to fall over during 'Numb', which has the unfortunate refrain "I make music to numb your brain" (a red herring, because it's the best track on the record - the alluring flip-side to Frank Ocean's 'Novacane'); and Adam Levine's pal Wiz Khalifa croaking a verse on the expansive, widescreen rap of 'Paradise'.

For something produced as a stop gap to keep the faithful, almost cult-like group of Cassie fans who otherwise have to make do with her debut, sporadic singles and leaked demos, it's a slickly constructed bunch of songs. The guest spots are drafted in to lend it some relevance, yet Cassie steals the show from even the more gifted cameo artists. Her delivery has a real flow, able to flit between that mocking, domineering Rihanna tone on 'Take Care...', trying to upstage 'S&M' for dirtiness on 'I Love It', moaning the titular phrase between Fabolous's rhymes, and then unleashing a rat-a-tat of her own lyrics.

Even when she's playing the part of the gangsta's moll this is Cassie's show. She has a magnetism that explain why people are still so eager to listen to anything she touches, and for the most part this could serve as a solid – if different – follow-up to her first album. 'Sound of Love', RockaByeBaby's stand-out, actually goes a way to bridge the gap between her sugary R&B to the world of brash hip-hop; like a Clams Casino beat fleshed out, she switches effortlessly between rhyming and serenading. The next chapter in Cassie Ventura's strange tale is going to be worth checking out – whenever it comes.