At this stage of their existence, Ghost have become engrained in contemporary heavy metal culture. Emerging in 2010 with their debut, released through Rise Above and titled Opus Eponymous, the cloaked troupe, led by the masked pontiff known as Papa Emeritus I, reminded us that metal was originally all about mystery and escapism. With Alice Cooper-esque pageantry, faux-Satanic imagery, and an unabashed love for proto-metal and catchy pop hooks, Ghost stood out in a scene that had become all too serious – a scene too focused on technical chops rather than strong songwriting and engaging old-school entertainment values.

Ghost offered a subversive alternative to the norm of the times: a cult of unknown, one which rapidly amassed many followers and detractors (famous and otherwise), both separated by their love/hatred for Ghost's somewhat rudimentary, yet refreshingly hook-laden music of their debut and the spectacle of their live shows. But for those who criticised Ghost for cheap aesthetic tricks and for musically pillaging legendary artists like King Diamond and Blue Öyster Cult (the latter being a constant comparison that has never sat right), they missed the point: Ghost, while clearly maintaining the devilish tongue-in-cheek approach that characterised the careers of Alice Cooper, Venom, et al., are a serious band with a shrewd game plan and the songwriting potential to execute it.

2013's Infestissumam, the Swedish nameless ghouls' (then known as Ghost BC in the US for legal reasons, a dispute which was resolved this year) major label debut, was a daring effort which hosted some of the band's best songs, but it also contained some tracks that didn't quite come off as planned, thus reducing the potency of the Nick Raskulinecz-produced record. However, in spite of its unevenness, Ghost's willingness to take risks to expand their sound was worthy of respect, and their second album charted number 1 in their homeland and their status worldwide grew with every subsequent chime of the monstrance clock. Noteworthy appearances at Coachella Festival in the US and Download in the UK followed, as well as a large North American tour, an EP of cover songs produced by Dave Grohl (If You Have Ghost), and some marketing ideas that would make Gene Simmons' mouth water (A Ghost dildo, anyone?).

In May this year, VHI aired a video from Ghost heralding the start of the promotional campaign for their third album, Meliora. The advertisement announced that Papa Emeritus II, the band's singer who allegedly took over from Papa Emeritus I prior to Ghost's second album, was "fired" and that his younger brother by three months, Papa Emeritus III, was declared the band's new frontman. Depending on your feelings for Ghost, this back-story tomfoolery will either make you roll your eyes and laugh or cause you to continue to dismiss this band as a "joke act". For those willing to stick around, the first song from Meliora, 'Cirice', was released as free download at the end of May.

For 'Cirice', the occasional prog rock turns that made Infestissumam an ambitious, albeit flawed album have been curtailed, and instead the track leans more so on direct muscularity. After an ominous intro, aided by the tolling bell of a ride cymbal, acoustic guitars and inconspicuous strings, the bullish central riff stomps forth, recalling Black Album-era Metallica, with Papa Emeritus III's sickly sweet vocals building towards one of their strongest, catchiest choruses yet. Upon hearing Meliora in its entirety, 'Cirice' is an appropriate lead-in to what Ghost have set out to achieve on their third album: to quieten the experimentation of Infestissumam to benefit songs that, like those of their debut, place greater emphasis on vocal melodies and classic song structures; and, also, to finally convince the naysayers that Ghost are a worthy metal band, capable of writing heavy riffs.

Meliora is Ghost's most modern-sounding album yet, although they continue to mine the past for inspiration. An ode to absinthe, musically, 'Spirit' owes a debt to Hammer Horror, Camel's Moonmadness (especially the keyboards), and a wealth of other 70s signifiers, all of which are evident, but complimentarily so. Papa III's vocals are, once again, the main focal point of the album, and on 'From The Pinnacle To The Pit' and 'He Is', the singer's devotion to the dark side conveyed through hymn-like hooks that shine like a diamond sceptre. His all-inclusive, chant-along vocals during the organ-led section of the former is an album highlight, and he turns the rather simplistic 70s classic rock structure of 'He Is' into a stirring love-song to Lucifer – indeed, it's one track that the overused BÖC reference rings true for.

But given the rigid stylistic direction of Meliora overall, Ghost seem to be writing for the expectations of the general metal community with songs like the stock metallic chugging of 'Absolution' and the AC/DC-baiting 'Majesty'. Such safe playing prevents Meliora from being something truly special. Until Ghost learn how to balance out their two sides – the band who wants to disappear into prog rock rabbit holes and shortly thereafter reappear in Satanic glam rock garbs; and the band who wants to set heads banging while their singer soars amorphously above the milieu – will never live up to their potential.

Tracks like 'Mummy Dust', 'He Is' and 'Cirice' once again show how eerie and entertaining Ghost can be when they get it right. Yet the general songwriting self-containment from a band who have shown glimpses of their ability to successfully incorporate atypical ideas, dilutes the experimental side we'd hoped would have been honed to stunning effect after Infestissumam's thirst for adventure. For that reason, Meliora, as a complete artistic statement, is the sound of a talented band relying solely on their well-established strengths out of fear of failure. Indeed, closer 'Deus In Absentia' stacks as many Ghost-worthy stereotypes as possible into one song – as close to a cringeworthy Ghost pastiche as it gets, replete with ineffectual choir singing that is more hackneyed than bombastic.

When it comes to bands with gimmicks like Ghost's, interesting visuals and sharp interview responses will only get you so far. To survive long-term there must be substance to supplement the shtick, and it's clear that Ghost understand this, as they have penned plenty of strong tunes since 'Ritual' bewitched us all in 2010. Unfortunately, to date, the overall quality of their recorded output has yet to herald anything close to resembling a complete masterwork. Maybe next time Ghost's "pursuit of something better" will strike the sacred balance between satisfying the congregation's expectations and achieving artistic free will.