The Blissful Symphony are a small cadre of Noise Marines wholly dedicated to the Prince of Pleasure. Formerly space marines of the Sons of Macragge up until late M39, these renegades have given their minds, souls and bodies to Slaanesh.

Much like Noise marines of other warbands, the Blissful Symphony's armour adheres to no known uniform or camouflage scheme, in fact, the squad intentionally goes to battle in the brightest, eye-catching colours possible, so their enemies can witness their beauty and combat skills more easily in combat. Naive tacticians may see this as a significant weakness, but in truth their armour patterns have a hypnotic, psychedelic effect, rendering those of weaker wills utterly transfixed upon sight. Targeting matrices and Servitor-crewed weapons are also affected in some unknown manner; it is theorised to be some form of radiation or signal emitted from the weaponry of this unit.

The armour worn by members of the Blissful Symphony is a typical combination of patterns, field modifications and bespoke parts common amongst traitor warbands. Most of the armour is a mix of MKIII, IV, V and VI. Uniquely amongst renegade forces, the group makes use of stolen MKX power packs, likely stolen from Primaris combatants. The most likely need for this high-tech imeprial equipment is to power their sonic weaponry.

Initial observations show that the weapons used are built from ancient Volkite weaponry; a precursor to the more common Bolter. It is most certainly cosmetic, as the weapon's projectiles and wound patterns found on victims show no resemblance to the Volkite's deflagration effects. The modified armaments, fuels by the overcharged MKX power packs (evident by the glowing vents visible in pict feeds) convert the power into blasts of sonic energy. The cables trailing from each weapons also feeds back to the user, providing intense ecstatic effects.

The current whereabouts of the unit are yet to be determined, although rumours persist they have either thrown their lot in with the Warmaster, or are gathering new recruits to launch a crusade of their own.