The progressive metal band INTRONAUT has astonishingly been making music for over 15 years. It seemed like only yesterday the band released their debut "Void" with its more post-rock orientation and strictly distorted vocals. Now, with their six full length album "Fluid Existential Inversions", the band seemed to have gone through something of a metamorphosis into more progressive territory and featuring so many clean vocals one could scarcely recognize them.

Unfortunately, they have also gone through a bit of a lineup change in that time as well. Gone is original guitarist Leon Del Muerte - leaving to focus more on project MURDER CONSTRUCT - being replaced with Dave Timnick. Gone as well is original drummer Danny Walker - allegedly due to a domestic abuse issues - and instead this is first album to feature Alex Rudinger, who played live with The Faceless, Whitechapel and Revocation. Due to his schedule, he has only committed to being a session member - agreeing to play a few live gigs as well - but the band hopes to make him a permanent member.

I agree with that decision, whether it was the drummer change or the addition of more synths, but this release is huge step forward in terms of growth. While the stop-and-go MESHUGGAH-inspired chugging riffs are still present, they seem to have abandoned most of the shoe-gazing elements that weighed down much of 2013's "Habitual Levitations". They are still there, but scaled but in such a way that they don't become overly repetitive and dull.

After an introductory opening track ("Procurement of the Victuals"), "Cabensis" pleases the secret drummer in all of us with Alex Rudinger's stellar blistering drums with both distorted and harmonized clean vocals walking through many different tonal feels throughout the song. This showcases an amalgamation of the original INTRONAUT sound and preparing the listener for their transition to loftier and more progressive sounds to come. "Contrapasso" dives further into the prog elements with echo-y voice samples, guitars that sound like clockwork and atmospheric synths in the breakdown, some really interesting lead lines near the end and even a guitar effect that gives it the effect of slide whistle to close the song.

The onslaught of guitarists Sacha Dunable and Dave Timnick is absolutely awesome in their attack. From the crushing dissonant chords in the intro to "The Cull" to the jazz chords later in the song, it shows the versatility of their craft. But they aren't just masterful axemen, their Alice in Chains-style dual harmonies during clean vocal runs are amazing and add that perfect ethereal touch. Joe Lester is even coming up with intriguing bass grooves underneath all the craziness, he is an underrated and underappreciated element that was a welcome discovery on subsequent album spins.

Adding drummer "Alex Rudinger" on as a permanent member would be a welcome addition after hearing what he can bring to the table here. Nothing ever becomes stale, they keep a shoe-gaze post-rock mood for the perfect length of time before going somewhere completely unexpected. Hearing them expand their sound, furthering their use and expansion of their clean vocals, continuing to deliver complex polyrhythmic, jazzy variety and the addition of more progressive makes for an excellent listening experience.